I echo Eric's opinion.
Every time I've gotten a bigger aquarium than I've ever owned, while shopping it seems huge! Then I get it home and its huge! 3 months later it's just my big tank. And 2 years later its not big enough. Every. Single. Time.
And, PetCo is having their 50% off sale right now. One of them near me had a 6' 125 Gal regularly $999, on sale $499.