Tearaway is an unbelievable $20 through Amazon right now
Developer Media Molecule (the original LittleBitPlanet devs) launched the PlayStation Vita exclusive late last month, which means you can get a still new release at half price by purchasing a download voucher. If you have the space on your memory card. To be honest, I'd probably go buy a bigger memory card just for this game.
How often do you have an excuse to dust off your Vita, anyway? We gave Tearaway a 9.5 out of 10.