hi, ebay or craigslist or a fish forum in your state that has listings for tanks ect for sale will be your best bet for a quality tank over 100 gallons. i was at one of the lfs
i go to lot that deals in fresh and salt water and they had nice 90 gallons with hood and stand on sale for just under 1000 bucks. to me it seem anything over 75 gallons and the prices go sky high for some reason. so unless you have to have a brand new tank id look for a gently used one cause you can find a nice tank and save hundreds of dollars.