I may be thinking about a 20 gallon high myself! I dream of a 40B though but no more tanks! I just need a 20 gallon for a fry tank/breeding tank. Would be cool to buy a couple and make a quarantine rack in the garage.... oh I dream but sadly don't have the money, time, or space at the moment!
For the record, PetCo has this sale every two to three months without fail. I spoke to the manager at our local store and he confirmed it is not a random occurrence and they need to clear overstock. It's intentional. If you cannot afford one now, start budgeting and it will be back in 2~3 months. If you don't believe it, search the forums and you will see it is regular as clockwork.