Howdy,
To add my two cents - I used Priceline once, needed a car for 2 days and 1 hour. Got charged for 3 days. I don't need that kind of hassel.
Like many of us, I don't pay for my own travel. But if I had stuck a clients accounting department with a bill like that - they would have pushed back - and I'd end up eating it.
My best tip - call the hotel/car rental from the airport. Often I've gotten walk-up rates that beat anything I could do online/advance res. (Drake for 95, Palmer House for 74 - and with Diamond Status - I end up with a suite).
Keep the faith,
Pakse