アーキテクチャ・意思決定比較表
Slack と SAMA のデータ構造、運用コスト、ライセンスリスクの違いを詳細に分析します。
SAMA’s numbers tell an honest, slightly less flattering story than some of the other self-hosted comparisons on this site: at every team size we modeled, Slack Pro comes out cheaper in direct cost, and the gap only really narrows — not reverses — once you’re comparing against Slack’s pricier Business+ tier at 100+ users. SAMA is a legitimate lightweight alternative, but the case for it has to be data sovereignty and control, not a strong cost argument at typical team sizes.
Slack Official Plans: A Detailed Overview
Slack offers several tiers, each designed to cater to different organizational needs, with pricing models that incentivize annual commitments.
| Plan Name | Monthly Price (per user) | Annual Price (per user/month) | Key Highlights |
|---|---|---|---|
| Free | $0 | $0 | 90-day message history, 10 app integrations, 1:1 audio/video calls only |
| Pro | $8.75 | $7.25 | Unlimited message history, Unlimited integrations, Group calls up to 50 |
| Business+ | $15.00 | $12.50 | SAML SSO, Data exports, 99.99% SLA, 24/7 support |
| Enterprise Grid | Custom pricing | Custom pricing | Org-wide deployment, DLP integration, HIPAA compliance, eDiscovery, dedicated support |
Pricing verified as of 2026-06-24 from slack.com/intl/en-gb/pricing.
Hidden Costs of Slack
Beyond the advertised per-user fees, several factors can inflate the total cost of ownership for Slack:
- Per-Active-User Billing: Costs scale directly with headcount. Even inactive users might incur charges if not properly managed, and the temptation to add everyone for convenience can lead to budget overruns.
- Slack AI Add-on: For advanced capabilities, the Slack AI add-on costs an additional $10 per user per month, significantly increasing per-user expenses for teams seeking AI assistance.
- Large File Storage Limits: Lower tiers may have limits on file storage, potentially requiring upgrades to higher tiers or the use of external storage solutions, adding complexity and cost.
- Integration with Enterprise Systems: While Slack offers vast integrations, connecting to complex enterprise systems (e.g., custom CRMs, internal tools) might require additional development effort or third-party middleware, incurring further costs.
Total Cost of Ownership (TCO) Analysis for SAMA
SAMA is a free and open-source self-hosted chat server, offering a robust alternative for organizations prioritizing cost control, data privacy, and infrastructure ownership. While the software itself is free, there are TCO considerations for hosting, maintenance, and engineering support.
Cost Trade-offs at a Glance
Hosting & Server Resource Estimation
Estimates assume standard cloud providers (e.g., AWS EC2, DigitalOcean, Vultr) for typical resource allocation.
- Small Teams (5-20 users):
- Resources: 2 vCPU, 4GB RAM, 50-100GB SSD storage.
- Estimated Monthly Hosting Cost: $20 - $50 (e.g., a basic VPS instance).
- Medium Teams (20-100 users):
- Resources: 4 vCPU, 8GB RAM, 200-500GB SSD storage.
- Estimated Monthly Hosting Cost: $50 - $150 (e.g., a mid-range VPS or small dedicated cloud instance).
- Large Teams (100+ users):
- Resources: 8+ vCPU, 16GB+ RAM, 1TB+ SSD storage (potentially distributed/clustered setup).
- Estimated Monthly Hosting Cost: $150 - $500+ (e.g., larger cloud instances, managed database services, CDN if needed).
Maintenance & Engineering Support Estimation
This accounts for initial setup, routine updates, monitoring, backups, security patches, and troubleshooting. We assume an average internal engineering cost of $75/hour (fully loaded).
- Small Teams (5-20 users):
- Estimated Monthly Engineering Effort: 2-4 hours (e.g., initial setup, quarterly updates, basic monitoring).
- Estimated Monthly Engineering Cost: $150 - $300.
- Medium Teams (20-100 users):
- Estimated Monthly Engineering Effort: 4-8 hours (e.g., more frequent updates, proactive monitoring, minor troubleshooting).
- Estimated Monthly Engineering Cost: $300 - $600.
- Large Teams (100+ users):
- Estimated Monthly Engineering Effort: 8-16+ hours (e.g., dedicated server management, scaling, security audits, advanced troubleshooting, potentially dedicated DevOps time).
- Estimated Monthly Engineering Cost: $600 - $1200+.
Comparative TCO Table (SaaS Fees vs. Self-Host Infrastructure - Annual Estimates)
This table illustrates the annual TCO comparison between Slack’s Pro plan and a self-hosted SAMA instance.
| Cost Component | SAMA Self-Hosted TCO (Annual) | Slack Pro TCO (Annual) |
|---|---|---|
| Software License | $0 | $7.25/user/month (annual billing) |
| Hosting Costs | $240 - $6,000+ | $0 (included in SaaS) |
| Engineering Support | $1,800 - $14,400+ | $0 (included in SaaS) |
| Total Annual TCO Range | $2,040 - $20,400+ | $87/user (fixed) |
Scenarios: Cost Comparison for Teams
Let’s evaluate the annual costs for different team sizes, assuming Slack Pro and SAMA’s estimated TCOs.
Scenario 1: Team of 5 Users
-
Slack Pro: 5 users * $7.25/user/month * 12 months = $435 per year
-
SAMA Self-Hosted (Small Team):
- Hosting: ~$35/month * 12 months = $420
- Engineering: ~$225/month * 12 months = $2,700
- Total SAMA TCO: $3,120 per year
-
Analysis: For very small teams, Slack’s convenience generally outweighs the TCO of self-hosting, unless specific privacy or control requirements are paramount.
Scenario 2: Team of 20 Users
-
Slack Pro: 20 users * $7.25/user/month * 12 months = $1,740 per year
-
SAMA Self-Hosted (Small/Medium Team):
- Hosting: ~$50/month * 12 months = $600
- Engineering: ~$375/month * 12 months = $4,500
- Total SAMA TCO: $5,100 per year
-
Analysis: Slack remains more cost-effective for a 20-person team when considering direct financial outlay. The engineering overhead for SAMA is still a significant factor.
Scenario 3: Team of 100 Users
-
Slack Pro: 100 users * $7.25/user/month * 12 months = $8,700 per year
-
SAMA Self-Hosted (Medium/Large Team):
- Hosting: ~$200/month * 12 months = $2,400
- Engineering: ~$900/month * 12 months = $10,800
- Total SAMA TCO: $13,200 per year
-
Analysis: At 100 users, the gap between Slack’s direct cost and SAMA’s TCO begins to narrow. SAMA’s cost is higher, but the per-user cost ($132/user) is closer to Slack’s ($87/user), considering that SAMA provides full ownership and control. If Business+ features (SAML SSO, Data Exports, 24/7 support) were needed from Slack ($12.50/user/month = $15,000/year for 100 users), SAMA would be more competitive in overall TCO.
When Does Paying for Slack Actually Save Money?
While SAMA offers significant potential for long-term savings and control, Slack’s SaaS model provides value that can translate into savings, particularly when:
- Engineering Resources are Scarce: If your engineering team is small, fully allocated to product development, or lacks expertise in self-hosting and maintaining communication infrastructure, the opportunity cost of dedicating resources to SAMA can outweigh Slack’s subscription fees.
- Rapid Scaling and Flexibility are Key: Slack handles scalability, upgrades, and maintenance seamlessly. For rapidly growing companies, avoiding infrastructure headaches allows teams to focus on core business functions.
- Advanced Compliance & Support Are Critical (Without Internal Expertise): For organizations requiring stringent compliance (HIPAA, eDiscovery, DLP) or 24/7 enterprise-grade support (Enterprise Grid, Business+), Slack’s managed service can be more cost-effective than building and maintaining internal capabilities to meet those standards.
- Extensive Integration Ecosystem is a Priority: Slack’s vast app directory and well-documented API reduce the effort needed to integrate with a wide range of third-party tools, which might require custom development or workarounds with an open-source solution.
- Risk Aversion to Infrastructure Management: Offloading the responsibility of uptime, security patches, and data backups to a dedicated SaaS provider mitigates operational risk for many organizations.
Final Purchasing Recommendation
For most teams, Slack Pro is simply the cheaper option here, and it’s worth saying plainly rather than manufacturing a false trade-off. SAMA earns consideration specifically at larger scale, when compared against Slack’s pricier Business+ or Enterprise Grid tiers, and specifically for teams that already value data ownership enough to accept a real (if narrowing) cost premium for it.
Cost and pricing analysis verified as of 2026-06-24. Self-hosting costs are estimates based on standard cloud providers.
よくある質問
How do Slack's Pro and Business+ per-user rates and hidden fees compare to the cost of deploying SAMA?
Slack's licensing costs scale quickly at $7.25 to $8.75 per user/month for Pro, $12.50 to $15 for Business+, and an additional $10 per user/month if you want the Slack AI add-on. SAMA is completely free of licensing fees under the MIT license, allowing you to deploy their Nodejs/Docker stack on your own hardware. This self-hosted model completely bypasses Slack's per-active-user billing, though you must budget for your own server infrastructure.
If our team is hitting Slack's free tier limits on message history and integrations, how does SAMA address these constraints?
Slack's free tier locks your message history after 90 days and limits you to 10 app integrations, forcing a paid upgrade to the Pro tier at $7.25+ per user/month to unlock them. SAMA, which scores an 8/10 in feature overlap as a self-hosted chat alternative, has no built-in paywalls or integration caps. Deploying SAMA's Nodejs/Docker server allows you to retain unlimited message history and configure custom integrations, bounded only by your own self-hosted storage.
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機能と価格データは公式ドキュメントと料金ページを出典としており、最終確認日は 2026年6月24日 です。 誤りを見つけましたか?お知らせいただければ修正します。