There are exceptions, but I find myself never wanting more than a 6pk of the same beer. I get bored of the style or just that particular beer at that point, and then I want something new. As far as price, $13 for a 6/4pk and $8 for a bomber is typically where I draw the line. Anything above that price range I'll buy a single or look for it on tap. If I'm going to buy something above my price range it comes down to how much I like the style, hype, reviews, and opinion of the brewery. I also try to limit myself to about $30 a paycheck.