You should be aware what you're doing is a violation of priceline.com's
terms of use, section 4, which explicitly forbid this sort of bidding, also known as speculative bidding:
You may only use this Site to make legitimate reservations, purchases or requests to purchase the products or services offered (each, a "Request") and shall not use this Site to make any speculative, false or fraudulent Requests or any Requests in anticipation of demand.