There are a couple web sites out there that can help with possible hotel ID's, previous prices won/paid, and bidding strategies. Not sure if links are allowed but search for better bidding and trip ducky.
An example, I used priceline and for 2 upcoming 1 night trips I got hotels with regular prices of 100/night for <50, and got the ones I thought I would get.
It is pay up front, so make sure you are FIRM on your dates.