If you want something cheap, get a GoPhone. That way you don't have to sign a contract, and you can use it on post-paid with no issues. The direction that post-paid is moving in is very clearly high-end smartphone or take a hike, and the customers who can deal with not having an iPhone 4, SGS II, Atrix 2 or that sort of device will be on prepaid.
Happy AT&T customer and addicted Speedtester in CT
AT&T iPhone 4s- Primary phone with camera disabled for work
AT&T Galaxy S7- Data-centric phone for outside of work
If you text while driving, you're an idiot. End of story.