Contracts are not available on any plans anymore. You will need to get a phone on device payment plan.
The contract price was misleading anyway. It may have seen you were getting a cheap phone, but if you are on any newer plan, a contract phone ended up costing you more money! If you had a contract your access fee is $40 instead of $20. Over the course of 2 years, that added $480 to the cost of your phone, more than negating the cheaper price you thought you got.