iPhone 5! Dirty cheap?

[Prototype18]

Hi guys.

I have 2 iphones 4S and 1 3GS. I use them everyday and cant be more happy.

But now im facing iphone 5.

I found them on eBay (also those 3 phones were bought on eBay) for 600$ shipped.

BUT they have bad ESN.

Just 1 short answer as googling it couldnt clarify me.

Can i use them outside US Ex in Albania with GSM mobiles. Im handy with jailbreak / flashin / Gevey etc.

Thank you !