If I buy and unlocked Iphone, Do I have to pay all at once or can I pay monthly?

I want to buy and unlocked iphone for 549. Do I have to pay all of it right there and then when I buy it, or is there like a monthly payment thing i could do to pay it off?

You have to pay all at once

You have to pay all at once. But, if you want to pay it monthly, you can put this purchase on a credit card, and pay credit cart payments every month until you pay it off.

All at once.

Best thing would be to get a cheap ATT iphone (locked) and then buy a Factory iPhone IMEI unlock service from eBay sellers. I have used them and I have gotten it unlocked in less than 6 hours. Connected it to iTunes and voila iTunes unlocked the iPhone

http://www.ebay.com/...0984052698