I'd say the difference is that more expensive champagne can taste much better than cheaper champagne, so you could be drinking it alone or with family or whatever just because you like the taste.

well i was thinking of something along the lines of Kristal, well overpriced, the difference between that and an average priced champagne (not nessecarily the cheapest one) being the show off part....

Im not too sure about the whole thing now i think about it, whose to say the guy covered in bling or buying the brand new ferrari isn't buying it just for his own sake, i spend more than i need too on clothes (as in i don't wear rags or knit my own) so this is as much show off as buying bling or similar but i buy it almost entirely for my benefit...