My 375g acrylic is 1" thick and the weight isnt a problem. 4 strong people can move it. I would be worried if it was any thinner, especially if you plan on keeping fish that will get big and thrash around.. My 180g acrylic is way thinner and bows real bad. It's in my fish room so if it breaks o well I will be upset about the fish loss not the tank or water damage.
1" acrylic is really hard to come by because its a petrolium (sp) product, and as the price of a barrel of oil goes up, so does acrylic. More and more tank makers are looking to alternative materials to help save in costs, and thats why you can find new tanks for fairly cheap.
I paid $1k and It came with filters and everything. I think it was an excellent deal considering the original price in 95' was $7k and they did a bid for the exact same tank (1" acrylic) for $13K.. If you can believe it. I was curious of what it was worth so I had them do a fake bid.. This included installation and shipment for about 500 miles.
I use glasscages.com as a pricing barometer for large tanks now. IMO, they are unmatched... unless you got the 'hook up'
The scratches should be of no concern to you, as they can easily be fixed. It should give you leverage in price negotiations though.. Depends on your area too.. in SoCal this tank isn't worth much.. in my neck of the woods people would pay thousands you don't see em that big here often..
