A couple of years ago LLM prompts really were incredibly cheap and falling in price. OpenAI's own models had fallen in cost by a factor of about 1000x since GPT-3.
They were also cheap because many of the things you might want to do with an LLM took in the order of a few thousands tokens, at most.
Then coding agents happened, and suddenly we had a reason to burn 100,000s or even millions of tokens on a single task. Stuff got expensive!
(Classic Jevon's paradox right there.)
It feels to me like that's trending back down again though. DeepSeek and Kimi are massively less expensive than OpenAI and Anthropic, and almost as useful.
OpenAI dropped the price of Luna by 80% the other day, and it's proving very capable of exploring codebases and generating quite competent code.
So I don't think advanced AI that can help debug and maintain software will stay out of the reach of most people for very long.