There is plenty to do in hobart on weekends.. lots of sights to see.. moutain summits, port arthur and a host of other things to do see and enjoy
theres some cheap syd and cbr in red-e deals at the moment. check them out...
if you want a cheap option and you have the time.. bus could also be an option/differnt approach!
I am in the process of planning my tassie to-do list for the weekend after you go..
if you need any help let me know!