$700 isnt bad! My guess is that the epoxy and glass was the expensive part? Might have to take a look at it sometime! I'm leaning that direction, as it would be easiest to get into the basement in sections rather than a complete tank...
It's a lot easier to just buff the scratches out of the 550g, for 750 that's a steal my friend has seen that tank it's nice. That tank must have cost 4000 new. If only my basement was done I would by it.