A few thoughts... 1) "Best Price Guarantees" are marketing tools that usually come with many strings attached. The point is that it sounds good, but the company rarely has to honor it. So you don't want to trust such a guarantee, no matter who gave it. 2) At a 2.5* rating, I'd be wary of using Priceline because the quality of the hotels in this category can vary quite a bit. At a minimum, I'd check this site's Priceline hotel list for the zones you are bidding on and make sure that ALL the hotels you might end up in are of acceptable quality and in a good and safe enough location. 3) If quality varies, you might be better off using Hotwire because you can usually narrow down which hotel you are going to get. So the risk decreases. 4) Regardless of whether you use Priceline or Hotwire, you want to get rates for all hotels that you might end up in as well as comparable hotels (e.g. from Expedia) and make sure not to bid more (or accept a higher price) than the lowest price for any of the eligible hotels on Expedia (after taking taxes and fees into account). 5) Due to the uncertainty about where you end up with PL or HW (you could always be the first to get a hotel not yet reported to this board) and because in case of trouble it is easier to deal with the hotel itself than with PL or HW, I would only use PL / HW if I can get a significantly lower price there than for any eligible hotel on Expedia. If you can't get a significantly lower price using an opaque product, might as well know what you get before you buy. There is more room for large discounts (dollar wise as opposed to percentage wise) at higher rated hotels, so PL / HW seem more attractive to me for these higher rated properties. 6) Although Expedia is my benchmark, I hardly ever book through them because you usually get the same rate when booking through the hotel's website directly. Again, in case of trouble a resolution is easier when less parties are involved. So bottom line: don't trust best price guarantees and do your own homework. I hope your future experiences with opaque products will be more pleasant.