When you have the successful hotel bid and they tell you the price of the rental car (I am referring to the page that has your successful bid accepted, not the pages that refer to it), they are obliged to give it to you. They don't say it is a possible price - they say it is the price - and you can go through every class of vehicle. They link you to a bidding form, not an order form. Often, Economy will be more that Full Size, for example. PL Customer service told me to offer the suggested price and if I didn't get it I should call them and they would take care of it. I've never had to. I did try underbidding but was never successful. Once in a while there is a location without bidding being possible and they simply link to a bunch of rental companies. The lowest acceptable price is constantly changing so the experience of getting lower at a later time is certainly one that I've seen too. Usually, the price keeps going down as the date approaches - unless they get sold out. It's good to decide what you consider a fair price and be happy with it.