Might check on driving to SA to pick up the Uhaul with a car dolly so you can drive both back to Austin 1-way with it. You need to look at what they charge per mile in addition to the daily rate and calculate what it would cost to drive here and back with it as that might be more expensive. Also, if you could fit the stuff in a trailer and have a truck with a hitch, that would be much cheaper as they are only like $30 to $50 a day depending on the size and lots of places rent trailers.