Rent a van through Priceline?

[melk]

We're going for 4 days in October and need to rent a minivan. So far through Dollar we got a price of $195 total, the cheapest we've found. But that's even more than we paid for a whole week last October.

Anyone ever use Priceline to rent a minivan? What is the procedure? What company(s) do you typically end up with? Any good or bad experiences with this?

Any info or tips you could give me would be greatly appreciated!