What is the best and cheapest brand to buy a apple iphone 4?

I'm getting a iphone 4 but my parents are trying to find out what the best and cheapest brand. My family wants to get a 3 or 4 family plan. My dad want to get me a contract plan but my mo doesn't. I need help! What brand is better? Cricket? T-mobel /sprint? ETC.

I would say go on Craigslist.com people sell their new iPhones for cheap I found a brand new I phone 4s $90 it's a good web site