Month one your API costs are fine. Almost suspiciously fine.
Month three you pull the logs and realize a huge percentage of requests are the same handful of questions asked slightly differently every single day. "How do I cancel." "Can I cancel my plan." "Cancellation." The model generates a fresh answer every time and you pay full price every time.
At low volume this is invisible. At any real scale it is a significant chunk of your bill that was never in the budget because nobody modeled for repeat traffic properly before launch.
The math is simple. First time a question gets asked you pay. Every similar question after that should cost nothing because the answer already exists.
That is what semantic caching does and it is the single highest ROI infrastructure decision for any AI Product with real traffic. I built it into synvertas.com along with prompt cleanup and automatic provider failover. One URL change to get all three.