I used the Bidding Helper. Started bidding from $55. Not being familiar with the resort fees (my last visit to the US was 10 yrs ago!), wasn't happy to read that I will be paying more at the hotel, but happy I still got a good saving.
I used the BiddingHelper.com. 4* bid went upto $103 with no luck. 3.5* on first bid of $75. Probably should have started lower but I am happy with what I got.