The very nice convention-oriented Seaport Hotel in Boston lists well over $200, but often has Priceline rooms in the $85-$100 range when no conference is there. This was both before and after 9/11 - I was supposed to be there 9/11-9/13 and never made it and I got it again for mid-October. Free high-speed internet access in the rooms, and yummy yogurt-covered cranberries in the minibar!

Go to www.biddingfortravel.com and look around for research about the city that you want.