Yeah that's a good deal! Only 1000 dollars for a 640 gallon tank?!?! If it holds water and the only things wrong with it are its a little dirty and has some chipping in the corners that's not bad at all. As long as you have the money and you're willing to put in the effort I say go for it. I mean seriously how many 500+ gallon tanks have you ever found that were $1000 dollars or less?