Boots are the one thing you don't really want to cheap out on, it's the difference between being in pain and having fun. The board and bindings on the other-hand you can almost always get for pretty cheap on craiglist or the like - and don't matter as much, especially if you are just getting back into the sport.
Not sure where you live, but I would suggest going into your local boardshop/sports store and getting a pair of boots that fit correctly. You can buy used, but it's sort of the same concept as buying someone else's hiking boots: they probably won't fit very well and will be very worn out.
In the meantime check craiglist and maybe post some setups that look promising on here and we can give you an idea of what to get.
PowderHound and TreeNinja