Don't look at hotels, look to rent a room somewhere. Went with my sister and stayed in a lovely room with kitchenette and ensuite, run by a youth hostel, and it was fine! No internet or room service or anything but perfectly adequate and we had an amazing time. Also, get a coach from the airport to Venice. It's miles cheaper than a water taxi or bus and certainly cheaper than a normal taxi. Venice is actually very cheap if you don't insist on going everywhere by gondola or eating in top restaurants. Also, definitely get a water bus to the different smaller islands, they're gorgeous!
xx
