Your best bet is to get what ever you want through Best Buy.
If you are hard on phones, do their $9.99 service plan, instead of the soon to be increasing to $8 a month Sprint TEP (should be called TEPEW - Total Equipment Protection Except Water). Sprint requires a deductible when making a claim for a lost or stolen phone ($100), and they will limit you to three claims, until they drop your insurance. Best Buy, unlimited claims, no deductible, cost $2 more a month. Your choice. If your good on your phone, hardly ever lose or drop in water, choose sprint.
If your phone is in good condition, sell it on craigslist. There are a lot of people who want a phone, right now, with no contract. I just sold my Optimus S for $100.00, the Tuesday after the Monday after the NS4G release. I live in Indianapolis, IN, if that matters for market consideration.