I got a pair of blue gouramis for three bucks at petsmart, and both for three apiece, and within a week(one in three days, the other in six), both were dead of dropsy... from what I understand it's common in gouramis... But in a proper tank where no other fish have a problem- it kinda irked me that both would kick off like that.
one reason I refuse to buy from PetSmart again...