I once got a mistake rate at the One & Only Cape Town through Expedia. Seem to recall I booked refundable as when I came across the rate, plans weren't sure. $67 vs. $670+ at the time. I was fairly nervous checking in but hotel made no point about it when I checked in. Great rate, didn't like the hotel... even at that rate. Caveat, this must be coming up on 10 years...