If I buy an iphone off ebay, can I use it with Straight talk?

See, I want to buy an iphone off craigslist, or ebay, and I was wondering if I can just use it with the company straight talk for my monthly bill, because it's really cheap. Or even virgin mobile, because their monthly bills are cheap. Because I don't know if you have to buy the phone off their websites in order to pay like $50 a month. So basically the question is, if I can buy my own iphone for cheap off ebay, and get a carrier like verizon, or straight talk and pay like 30-40$ a month, instead of buying the phone off their website? **See I'm 15 years old, and never really had a phone before, and I'm trying to convince my mom, to get me an iphone. P. S. Also if you could tell me the CHEAPEST PLANS OUT THERE** IF THE PLAN I ASKED DOESNT WORK!* thank you for all you answers!

I think sraight talk uses sim cards, if so, yes your plan should work

Ok, here it is… You gotta make sure the iPhone is unlocked. And it MUST be AT&T (or T-Mobile, they have iPhones right? I wouldn't know since it's not for my area anyway). You cannot use Verizon. Straight talk only sells SIMs for at&t and T-Mobile. And the SIM cards are around $50ish from what I've seen. They really bump up the price when it comes to smartphones. Also, compare prices between an unlocked and a straight talk one, but straight talk DOES sell iPhones. Yes, you can bring your own, but you gotta make sure it's unlocked and that you have the SIM. The cheapest plan on straight talk is $30. I will tell you now, that will not work. It's not compatible with smartphones. Their $45 plan IS compatible, so when you see $30 don't get all excited, lol. Also, here's some stuff about straight talk you need to know: they will violently throttle your data, so use wifi whenever possible. What I mean is, they will make your phone slow. All companies do, yes, but they have a "data cap", i.e. They say "ok, after using 2gb of data, we're gonna make your phone be slow as molasses!" Straight talk, however, don't actually SAY any kind of data cap so… They throttle you whenever they "feel" like you're using too much. And their customer service sucks, they barely know English. I'll include a link in the source box for you, supposedly these numbers might get you to someone competent (because of course straight talk doesn't include their florida number anywhere in the booklet, they want you to call India or wherever the hell it is, lol). But there's pros and cons for every phone company, at least this one is only $45! Good luck! -3 year Straight Talk customer.