Sorry to hear about that. It's so much work to replace the glass, especially if it's in a frame and since used tanks are half the cost of new, even right out of the store, I would buy a used tank. Used tanks can be awesome or junk. I always check the glass for scratches by looking at it from all angles with light coming from different angles. I won't buy if the silicon is very damaged, because that means it probably wasn't cared for properly.
The only time the front glass of an old aquarium ever cracked on me is when it was not supported correctly. It was high centered. High centering a glass tank is the surest way to crack the glass.
Of course I don't know how this tank was supported but it's certainly something to check when setting up the next tank.
Also, even when the stand is perfectly flat, a warped or weak floor will cause the ends to sink when water is added which high centers the tank. I typically err on the side of supporting the tank ends, even if there is only enough space to slide a thin piece of paper underneath the center line.
Hope this helps.