One of the top concerns for businesses considering private AI assistants is cost. "How much will this cost me per month?" The honest answer: it depends on how much you use it and how smartly you configure it. But with the right approach, most businesses spend $5-50 per month, far less than a ChatGPT team subscription.
How API Pricing Works
AI providers charge based on "tokens," roughly speaking chunks of text. Both your input (the question or prompt) and the output (the AI's response) count toward your usage.
A typical business message might cost:
- Simple question to a fast model (Haiku/4o-mini): $0.001-0.005
- Complex email draft to a standard model (Sonnet/4o): $0.01-0.05
- Long document analysis to a premium model (Opus): $0.10-0.50
At these prices, you'd need to send hundreds of messages per day to hit $50/month.
Strategy 1: Model Routing
The single most effective cost control strategy. Different tasks need different quality levels:
- Quick questions, short replies: Use the cheapest model (Claude Haiku, GPT-4o mini). These cost almost nothing.
- Standard business tasks: Use mid-tier models (Claude Sonnet, GPT-4o). Good quality at reasonable cost.
- Critical documents, complex analysis: Use premium models (Claude Opus). Worth the cost for important work.
With proper routing, 80% of your messages use the cheapest tier, 15% use mid-tier, and 5% use premium. This keeps average costs very low.
Strategy 2: Spending Limits
Every AI provider lets you set hard spending limits:
- Anthropic: Set monthly spend caps in the console
- OpenAI: Configure billing limits per month
- Google: Set budget alerts and hard limits
Set your limit at a level you're comfortable with. If you hit it, the assistant either stops working or switches to a backup provider. No surprises on your bill.
Strategy 3: Efficient Prompting
How you interact with your assistant affects cost. Some tips:
- Be specific. "Write a 200-word follow-up email to Sarah about the project" costs less than "write an email" followed by "make it shorter" followed by "add the project details."
- Provide context upfront. A clear, detailed prompt generates the right output on the first try instead of requiring back-and-forth refinement.
- Use templates. For repetitive tasks, create templates in your assistant's configuration. The assistant knows the format, so you only need to provide the variable details.
Strategy 4: Monitor and Adjust
All providers offer dashboards showing your usage in real-time. Check weekly for the first month:
- Which tasks are consuming the most tokens?
- Are there tasks routing to premium models that could use standard models?
- Is the assistant being unnecessarily verbose? (You can instruct it to be more concise.)
Real-World Cost Examples
| Business Type | Daily Usage | Monthly Cost |
|---|---|---|
| Solo consultant, light use | 5-10 messages | $5-10 |
| Small business, moderate use | 20-40 messages | $15-30 |
| Active user, heavy content creation | 50-100 messages | $30-60 |
| Multi-agent setup, high volume | 100+ messages | $50-100 |
These figures assume smart model routing. Without routing (using premium models for everything), costs would be 3-5x higher.
The Bottom Line
AI API costs are dramatically lower than most people expect, and highly controllable. The combination of model routing, spending limits, and efficient prompting keeps costs predictable and low, typically less than a single hour of your time per month.
The question isn't whether you can afford an AI assistant. It's whether you can afford not to have one, given the 10+ hours per week it saves.
Book a free discovery call and we'll set up cost-optimised model routing for your business.