Who decides the rates

When you use pay per click at Google, who decides how much it shoudl cost?

When you utilize pay-per-click of any type, it is the market that decides how much you will spend. As such, the people bidding for the key words bid against one another in an auction format. Thus, the more your competitors bid, the more you'll have to outbid them to get better advertising position.
I hope this helps!
The Surgeon's Advisor Team