2nd hand is the way to go. just get a decent condition tank and buy new or used if the price is right filtration. i have done that before with a 125g tank and it took quite awhile but great savings. ended up all in 600-650$ decor filters the whole nine yards minus fish. GL to ya as you may have to drive a bit, but the ferry out there is a great resource.
Hey did I miss the post with pics of this tank? lol
Yeah craiglist is a good way to get a large tank for a good price. You can also keep your eyes open on the Petsmart website. They have had sales where you buy online and then pick up in store with some good discounts. New tank with warranty is nice...