Have you tried selling to high-frequency traders / hedge funds? If they bite, it's probably not even worth having a low-cost/self-serve tier.
Everyone who is anyone in the finance space has been doing stuff like this since way before LLMs were a thing, and they've put a lot of time and effort into their tools. This suggestion is kind of like saying you should try to sell your lemonade stand to Coca-Cola.
Btw, Coca-Cola bought Minute Maid Lemonaide in 1960. :)