>>8989875315 bucks might last for a few sessions if you stick to Sonnet and don't swipe too much, and make a new chat for each session.
The biggest issue is that they charge for the tokens, not just output but also input, so the longer your chats get the more you'll be paying for each individual message.
Looking at the usage page is like a stab in the gut, the first few messages are dirty cheap so it feels like your creds are going to last forever, but at the end of the chat you look again and see that the last one was like 5x the cost of the first.