IPhone 4 working with metro pcs?

I just bought an iPhone 4 (sprint, iOS 5.1.1, bad ESN)
What do I have to do to get it to work with metro pcs?
Will the Internet and mms work?
I bought it for $165 mint condition just the phone plus got knows how much will cost to get it to work with metro.
was it a ripoff? What do you Guys think?

I don't know if Metro has an Iphone plan.