It all depends on the condition of the tank. If the glass is perfect & the seals are good this would be a good deal. If the glass is scratched or if the silicone is brittle (meaning you'll have to resilicone soon), try to get it for 10-20 less.
Fixing a leaking tank is not that big a deal if you are handy, but it is labour intensive & messy. I'd try to get the leaking tank for $50 or less.