Where can i buy an unlocked iphone?

Hi i'm currently with metro pcs and i have a windows phone but it totally sucks, so i would really like to buy and iphone and switch it to metro and i'm looking for something around $200.00. Also i don't care if its a 4s or 5. So please please help me! I've been looking everywhere for about a year!

1. MetroPCS was bought by T-Mobile a while back & they are in the process of phasing out.
2. Since metroPCS is a CDMA carrier you'd have to get a CDMA iPhone & in that case it is a matter of if they would activate it for you or not.
3. Unlocked models are always the most expensive configuration, starting at $649. You could check around eBay to see if you could find any for that price but it either would be an older model or one with some sort of problem.