Rates are all over the place, even for the same booking. I find Avis rates that vary by 50% for the same date and location, depending on the booking engine -- absurd! Generally Hotwire is the best if you don't care about which specific agency. But it varies a lot by date and location. And yes, many rates are double now compared to a year ago, until you find the "right" deal (and then it is less than a year ago). Product differentiation at its finest, I suppose.