A Gobbiebag from Bluffnix

Did you know there is a Goblin Shop in Lower Jeuno? =-O I didn't realize there was one until I stopped in for something (though I can't remember what it was now). I talked to a Goblin there (he smelled pretty bad actually) named Bluffnix. He told me he could increase storage in my bag without increasing its size. He said the "gobbiebag" is a secret of the Goblins and while he wouldn't show me how to do it, he said he'd do it for me if I brought him some items.