any tank for $1 per gallon is a good deal. the RTC on the other hand might pose a problem. try to trade it at your LFS for store credit sooner rather than later. don't wait until it's too big for the tank and you can't find anyone that will take it off your hands.
my ex left his RTC behind when he left. i expected him to come and get her long before now, but it hasn't happened (9 months and counting) and now she's too big for me to get her out of the tank she's in.