I am exactly the same as H. My friend has a designer watch (GucciI think), costing just over £1000, and I just don't get it. It tells the same time as my chunky funky 25 quid one from Argos! Mine's looks better,doesn't matter if I lose it and nobody's gonna mug me for it!
Same as bags. We women can be mugs at times. I have found a great source for copy bags (knock offs as they call them in the U.S of A). I like Marc Jacobs bags but refuse to pay the Harvey Nics price. When people ask me if its a genuine one, I tell them if they can't tell, then they don't need to know!
Now Champers is another story. I know lots of Cahmpagne can be really expensive, but IMHO, the more expensive it is, it tends to be drier, thus making it less palatable for my taste. So £28 is my max for bubbles!
P.S I am Scottish too, but by no means miserable. I just like value for my hard earned money.