Grok’s paid plans start at $15/month and $50/month for higher usage, with a cap...

https://wiki-global.win/index.php/How_Much_Does_X_Search_Cost_on_the_Grok_API%3F

Grok’s paid plans start at $15/month and $50/month for higher usage, with a cap of about 10 prompts every 2 hours to keep costs predictable. Note, there’s no free trial available, so you’ll want to be sure before committing to a subscription