Will gevey work with iPhone 4s Verizon bad esn?

I bought a iPhone 4s from a guy on the street for $75 and its got a bad esn so if I buy the gevey ultra s will it unlock the iPhone and allow me to use it with tmobile?

Probably not. Get the phone factory unlocked and use with T-Mobile or any GSM carrier. You can also get it flashed to CDMA carriers other than Verizon. You can mail this person (arghyle@rocketmail.com) who can help you get the phone factory unlocked or flashed to other carriers.