Justin, your best bet is to go to a local fishstore and ask them if they have any used tanks...they will understand that you need one that has not been treated with copper at all.
You will find, though, that most people sell used tanks for just about as much as a brand new one (and that you are sure has never had copper in it)...it might save you some money in the long run just to get a new tank!
Good luck, write if you have any questions!
Well, if you stock the tank with several hundred dollars of stock and it dies off due to a chemical agent used by a previous owner, you have managed to throw a lot of money down the can, right?
You will find that used tanks cost almost the same as new...a fifty gallon tank costs about 65 bucks...the used ones in the paper here yesterday were selling for 50. so, for 15 dollars you are going to risk all of the animals life? Doesn't sound to sensible to me, right?
Where do you live? Some of the folks here might be able to help you with suggestions of where to go in your home town. Also, Petco and Petsmart have much better deals when you go in to the stores than online. Another thing to try is at your LFS (local fish store), ask them at the counter how much it is for a basic 55 gallon tank, without the super-fancy stands they have on display. They might have better deals available than they have shown. If you find a good LFS and explain what you are doing, (don't rely solely on their info, do your homework and ask questions here) they might be able to cut you some deals since you are likely to give them repeat business. I frequent about 4 LFS's here in houston, and they all give me at least a 10% discount because I am in there all the time. Often times, I get better deals than that.