Codex limit hit, now what?

So I got the Plus model, but already hit the monthly limit? I thought I'd exchanged the monthly limit for an hourly limit, not an hourly limit with a bigger monthly limit. Now it's suggesting I pay $40 for 1k credits, but a monthly subscription only costs $20, so I'm confused. What's going on? I tried asking Google and it said $40 for 1k credits is typically a horrible deal. The business version of the plan only costs $20 and claims to offer "maximum codex tasks," but idk what that means, or why the plus and business plan both cost $20 but the business plan seems to come with more.