We provide a similar service for Godot instead of Unity, and 20$ plan being exhausted in one prompt on a top model like Opus sounds about right. That's the life when you pay API prices and can't afford 10x subsidies.
Is this true even for more targeted prompts that aren't about looking over an entire codebase or w/e? I just stick to my sub pricing and find good success on targeted requests, but I wonder if I would run up against things even then if not for subsidies.
Not sure if you meant Fable/Mythos instead of Opus, but I can comfortable work several hours a day using Opus on Max-Ultracode on the CC 10x.