Very hot and miss. I buy new tanks. Helps keep the cost of this expeiensive hobby down. I also reseal every used tank I get because I don’t trust it enough to risk water damage. Also I always have someone come with me for the exchange as since it’s a tank you always have to go to their house which is risky. Doing a used tank sale is a risk only you can say iif it’s willing to risk
I agree with what was said above. If you do decide to get it, aside from asking things like are there any leaks, scratches etc. also ask how old the tank is, if they've ever had any problems with it, stuff like that. It's also best to ask that the tank be full when you go to see it so you can see for yourself that there isn't a leak.
It can be. My 65 gallon came from a Craigslist ad, and it's worked well. I also bought a 20 long, but after spending way too much time trying to get it clean I loaded it on the back of my truck, drove to Pet Supplies Plus, gave it to one of the workers there, and bought a new one (fortunately it was during their $1.00 per gallon sale).