I cannot find the answer to this question. Im still debating to buy my galaxy s3 with tmobile or s3 with sprint. Sprint has a better value but tmobiles network in my area is amazing. Both phones are pretty much the same but tmobiles model is way more expensive. My question would be if I buy a s3 with two year contract. Could I unlock it with a third party source to use on my tmobile plan.? Does it have the sim card tray? The sprint model.