At 6 requests/user/day (totaling 450,000 queries/mo), running Customer support chatbot on Mistral Medium 3.5 costs $2,055.375 / month ($0.8222 / user / mo).
Customer support chatbot for a 2,500 active users (series a product) audience means 15,000 requests per day on average, each carrying 3,500 input and 350 output tokens at a 70% cacheable share — so the effective per-request cost on Mistral Medium 3.5 is $0.004568, of which $1,488.375/mo comes back from prompt caching. Per active user that's $0.8222/mo — the number to hold against your pricing tier and gross margin. Charging at least $4.111/user/mo keeps gross margin at or above 80%.
Quick answer
For 2,500 Active Users, Customer support chatbot on Mistral Medium 3.5 is modeled at 450,000 requests per month, costing $2,055.375 per month or $0.8222 per active user.
Method & trust
This projection combines the selected active-user tier, requests per user per day, input/output tokens per request, and the modeled cache share. It is an operating estimate, not a provider invoice; production traffic and retries should be measured against it.
Total expected API invoice for 2,500 Active Users generating 450,000 queries.
Direct inference cost per MAU to model your SaaS pricing tiers and gross margins.
Savings generated by exploiting 70% cache hits on prompt context.
| Model | Provider | Monthly Spend (2,500 Active Users) | Cost / User / Mo | Annual Spend | Context Limit |
|---|---|---|---|---|---|
| Mistral Medium 3.5 (Current) | mistral | $2,055.375 | $0.8222 | $24,664.50 | 256,000 |
| GPT-5.6 Sol | openai | $7,638.75 | $3.056 | $91,665.00 | 1,050,000 |
| GPT-5.6 Cyber | openai | $19,096.875 | $7.639 | $229,162.50 | 1,050,000 |
| GPT-5.5 Standard | openai | $7,638.75 | $3.056 | $91,665.00 | 512,000 |
| GPT-5.5 Pro | openai | $45,832.50 | $18.333 | $549,990.00 | 512,000 |
| o3-pro (Frontier Reasoning) | openai | $24,255.00 | $9.702 | $291,060.00 | 1,000,000 |
At 6 queries per user/day with Mistral Medium 3.5, the estimated cost is $0.8222 per monthly active user (MAU). Total monthly bill for 2,500 Active Users is $2,055.375.
Assuming a 70% cache hit rate on repeated system and context tokens, prompt caching saves $1,488.375 per month ($17,860.50/year) on Mistral Medium 3.5.
With a direct COGS of $0.8222 per user/month on Mistral Medium 3.5, charging at least $4.111 per user/month ensures an 80%+ software gross margin.