No, you’ve gotten confused between ChatGPT and AIPRM. ChatGPT has only the one plan - ChatGPT Plus @ $20 pm. But there’s also premium plans for the AIPRM extension, which are the multiple plans you are talking about. They are different things, from 2 completely different companies.
ChatGPT Plus gives you a little more access to ChatGPT
AIPRM Premium Plans give you extra features and functionality to however much access you have.
2 different products offering different benefits.