I got a very old 125 gallon for $50 about 4 years ago. I read up on resealing it and bought a nifty little tool at home depot that cuts out silicone and then helps to make the seams look even. It was a pain but it worked out great.
Moving the tank afterwards I cracked the bottom of the tank.
So, so, sad!! I started reading again and patched the bottom with glass and silicone. Then I began to worry and obsess about the repair and the safety of it.
I gave the tank to a guy who needed it for his fish breeding operation and he has been using it without issue these past 4 years.
Granted, it wasn't as tall as your tank but maybe I should have kept it???? The only problem I have ever had was with a tank that someone sealed with house type silicone. The antifungal stuff leached out and killed my fish.
Use your own best judgement. Good luck!