Can you factory unlock sprint iPhone 4s?

I'm buying an iPhone 4s from craigslist. It says the phone is Sprint but my network is T-mobile. Can I factory unlock it? Do you know much much will it cost me to unlock it?

Yeah you can do it see this and do it http://support.sprint.com/.../26497-101

There are several ways to unlock Iphone4s apart from Factory unlocking. You can unlock your Iphone4s locked sprint network using Remote unlocking method. Remote unlocking is the secure and easy way to unlock Iphone. If you are intersted in this method of unlocking your Iphone you can try this site http://www.mobile-unlocker.com/apple-iphone-4s/rs16wp9/. This is possible only if you bought your Iphone before Jan 26 2013. If you bought your Iphone after 26 January 2013 unlocking is illegal in USA so please contact your network/service provider and get their permission to unlock your phone. After getting the permission you can get the remote unlock service from that site. After unlocking your Iphone with Sprint you can use other CDMA networks.