Yeah any bumper will do, really. The Apple bumper I got for free last year because of the antenna issue still managed to tear on me. So I wouldn't be so focused on getting an OFFICIAL Apple bumper just because ... Well it's official. I ordered an $8 one from sw box. Far more better looking. We'll see how the quality turns out...
Best price is probably on Amazon with free two day shipping for prime users and no tax. But don't get any with a lower price than 29 99 (or whatever the Apple price is) because they will probably be fake.