Started the bidding at $120 in zone 6 (Mayfair - Soho) - got a counter offer at $161. Added free re-bid zones (1, 2, 3, etc) one-by-one and incremented my bids by $5 each time (I used the permutaion bidding system - closing the browser after each unsuccefull bid). Got a one-time offer from Priceline twice (!) to raise the price by $22 and re-try, which I rejected (and I was right - this saved me $12 on their first offer, the second one would even put me over the original $161 counter offer). The rates at this hotel start at 195 pounds/night on its website for the date in August I booked the room for.