I dunno if it matters if you stay in Venice or around Venice ...
I stayed @ Fusina CampSite
which was great. NIce clean , pretty much everything you need. There is regular bus service in the area and you take a ferry/water taxi to the city.
The only drawback would be its about 50 min from Venice..but the place is cheaper than staying in the city!
Oh and get ready for a party, it can get frikn wild over there!!!