Grok’s paid plans start at $20/month for up to 10 prompts every 2 hours, with...

https://smart-wiki.win/index.php/How_Do_Grok_API_Tool_Charges_Stack_on_Top_of_Token_Costs%3F

Grok’s paid plans start at $20/month for up to 10 prompts every 2 hours, with an option at $50/month for higher usage. There’s no free trial, so you’ll pay from day one