A couple of months or so ago, I tried the reverse bid just to see if it works well or not.
Apart from the numptie`s from the other end of the country who bid, my average seems to be £20-£30 off, or an outcall for the price of an incall.
The good advantage is that if you get the girl, like her and book again, there`s a good chance she will do it at the reduced rate again.