Cheapest temporary phone on AT&T with my current account?

I have a dying iPhone that is gonna kick it any second now.  And I have ~6 weeks left in my contract before I can get the iPhone 6.

I could always get a burner but want to make sure I get my calls on my current number.

What is my cheapest option where I can use a temporary phone with my current phone number?  Can I simply plug my microSIM into another super cheap AT&T phone I get off ebay?  Or Radio Shack? or Best Buy?

Don't let me down, CAGs.

It's been a few years since I've been with AT&T, but at least when I was with them you could swap the SIM card between phones without issue. But then again I had previously done that in a time before we had smartphones, so maybe that's no longer true. My inclination would say that you could but I can't say with any sort of confidence, sorry.

And I'll also offer you the "obvious" response before someone says it in a more douche-y way: "Have you tried calling an AT&T store?"

Yeah you can just get another cheap gsm phone. Just make sure it has the correct gsm bands for at&t if its an unlocked phone.

And I think all of iphones from the past couple of years use nano sim cards. And practically all other smartphones use micro sim. Just look online and make sure you know which one you have. If not you will have to go to an at&t store. And they will give you the correct size sim for free.

Yeah. Basically, just search for a phone that takes micro SIM and isn't locked to something like T-Mobile. You can pick up a used iPhone at GameStop and trade your dying one.

You can go to any store that sells go phones and just put your sim in that until the new iPhone comes out.

Thanks everyone.

Turns out the iPhone does use a nanosim. You can get an adapter for $1.50 on amazon.

Also my iPhone 5 is eligible for the just announced battery recall/fix.