Looks like GPT’s are free and ready for everyone. Here’s the email I received from open AI.
“Hi there,
We’re reaching out because you’ve built a GPT and shared it in the GPT store.
We recently announced that all ChatGPT Free users would soon be able to use GPTs in the GPT Store, in line with our mission to make AI technology accessible to all. Today, GPTs in the Store are now available to all ChatGPT users, allowing more than 100 million weekly active users to experience your GPT and the others in the store.
GPTs now use our newest flagship model, GPT-4o. Given the possibility of increased usage and behavioral changes with a new model, we recommend reviewing and testing your GPT to ensure it continues to perform as intended.
Thank you for building GPTs and introducing new ways to learn, have fun, and be more productive with ChatGPT.”