I've used Expedia several times for different trips.
I now check their site very often because in May of 2003, I did a search for lodging in Orlando and rubbed my eyes several times, pinched myself, thought I was dreaming....saw a five bedroom vacation home with its own pool for the rate of .... are you ready for this?....
$26 a night!!! I called their 1-800 number and asked if I booked it, was it true? They said that yes, they had to honor the price even though it was a mistake...and we spent a wonderful week at that house with my DH entire family (there were 12 of us!). By the time we divided the cost of the house between the four famillies...we had the cheapest trip to WDW ever.
So, I always keep looking for that slip up on their part...ya never know!