Looking to buy aquarium

Hello. I recently rescued a large fish from a scary situation.. he's living right now in a decent sized tub... but I'm looking for a aquarium for him as he can't go in my community tanks.... I'm not looking to spend a fortune as this was very much so a spur of the moment situation before who knows what would of happened to the poor guy. I'm looking for a tank 40-55 gallons.. and only looking to spend at most $1 per gallon. If you have a tank lying around that's in good condition and holds water with a lid I'll gladly take it off your hands to give this guy a tank that he deserves and desperately needs. Please contact me with information. Thanks so much in advance!!