Question 1

How much does it cost to run an AI chatbot?

Accepted Answer

With 10K users at 5 messages/day using DeepSeek V4 Flash, expect ~$3,000/month. GPT-5.5 would cost ~$33,000/month for the same workload.

Question 2

What is the cheapest way to use AI APIs?

Accepted Answer

Use budget models (DeepSeek V4 Flash, Gemini Flash) for routine tasks, enable prompt caching to save 80-90% on input, and limit output token length.

Question 3

How do I estimate my monthly LLM costs?

Accepted Answer

Multiply per-call cost × calls per day × 30 days. Use the free calculator at aicalc.cloud/llm-pricing/llm-cost-calculator/ to get estimates for all models at once.

How to Calculate AI API Costs