What's better contract or no contract?

The 2 year contract is iPhone 5 for 149.99 one time plus 51 dollars a month. The no contract is iPhone 5 for 579.99 one time or down payment of 99.99 and 20 bucks a month plus 42.50 a month?

Looks like you are referring to T Mobile. Math wise $579.99 up front plus $42.50 per month is identical to $99.99 up front plus $62.50 per month for a contract length of 24 months. However you should check to see if your phone comes unlocked should you pay entirely up front. Unlocked cell phones have way higher resale values when you sell them.

See the attached source for comparing buying at the Apple store versus at T-mobile stores. There are differences in incentives.

www.CaseCow.com - Phone Cases starting at $4.99

I have metroPCS and i pay $60 a month. Right now T-Mobile has a promotion of getting any phone at no contract. So let's say the HTC one is $500 and you can pay off the phone monthly with your phone bill. So when you first time get the phone you'll pay $99.99 for the phone then on the bill you'll pay $25 a month for 24months. & get LTE Speeds for unlimited talk text & data for $80 a month. Hope this helps.