You must read biddingfortravel to see what kind of hotels you may get in a particular Priceline zone and class before bidding. And then read the reviews of those hotels on biddingfortravel or Tripadvisor or elsewhere. If there's a hotel or two in that particular zone/class that has horrible review, then you shouldn't bid in that zone/class.

It's really no different from booking "non-refundable" rooms directly with a hotel or via other booking sites. You are still prepaying for a hotel room which you probably have never stayed at or seen. Unless there's something really unusual, you can't just get your money back because you show up and say you don't agree with its class ratings.