Propane fire pit

I am thinking I might want to get a propane fire pit for camping. I'm really tired of buying wood all the time. It's expensive, and, many times I end up with wet wood that burns like crap cause they leave it uncovered outside. I wonder if any of you have one, or, have an opinion on whether it's a good or bad decision. I can't imagine it's a bad thing, but I also wonder how often i'll need to refill the propane. I don't want to be getting propane everyday. I mostly like to sit out by the fire for a couple hours at night, so I would hope i could get atleast a weeks worth of fires on a twenty pound tank. Any opinions?