Hi, I am interested in buying an iPhone 5 from Tmobile for 679.99 (32 gb model) but not add the $70 unlimited service they provide but switch it for the sim card $30 unlimited prepaid plan. I know iPhone 5 is nano sim, I can just cut it. But the question is, when when I get the phone, can I not get the $70 plan with it and just slip the slightly modified $30 sim into the phone? just setting the $70 aside or is the iPhone's serial number or whatever is linked to the $70 sim that I will get? Thanks