I’ve had the same experience with the British Hotel Reservation Center. After arriving late due to flight problems I wasn’t paying attention and thought the British Hotel Reservation Center was an information service to travelers, rather than the for profit business / travel agency that it actually is. The most disappointing thing about the British Hotel Reservation Center is that they don’t just take a fixed commission (which would be fare enough), but instead just offer very expensive rates compared to rates that one could easily find elsewhere.
As the original poster pointed out, being prepared with telephone numbers to book directly with a hotel is the best strategy to get a good price. I’m not a fan of using travel agents or other intermediaries, however, if you have a Blackberry I suggest downloading WorldMate Live. Even with the free edition you can search hotels and actually make a reservation immediately using your Blackberry. My favorite part about this is that it’s free, the rates seem to be the same as good rates that I’d find though kayak.com or other online search and it’s perfect for booking one night when you accidentally get stranded there at the last minute and have no idea which hotels are nearby.