Where can I buy a cheap Palm Centro with no contract requirements? Read details.?

I have at&t and I've been looking on ebay and amazon for a Palm Centro (At&t) Because I hate my phone and I really want that phone but they're all cheap but they say like only one cent but you have to buy the service plan and I already have one. Where can I get one? Or a blackjack would b nice too?? But it'd have to be less than 100$