for three summers on the Ark i lived in a Wal-Mart (Ozark Trail?) tent that I rigged with extra tarps and lots of support lines. I was in a Pinon/Juniper woodland, so had lots of things to tie-off to, and the thing was ultra bomber and dry, plus cost me around $100 for three summers of living. Once I got a good woman (NOT a dirtball) we decked it out with an inflatable queen size air mattress. my tarpology skills are strong though, so if you don't how to rig a good tarp shelter this may not be for you.
that being said, i set it up in early June and took it down in mid august...if I had to take it down and put it up regularly i may go with something like this:
Big Agnes Big House 6 Tent at REI.com
we have it now for family boating and it's amazing.