I thought that too. There is a definite difference between some, maybe not compared to the difference in price though. With some products the difference in quality is certainly not that much.
My sister works in the prawn industry (no John), and they have different specifications (size, quality, colour consistency, etc) for the different levels of packs they produce for the supermarkets. In the past, she worked as a quality tester, testing bananas (no John), and melons (no John). If she worked in a sausage factory (no John), I'm sure she'd be able to sort you out (no John).
Correct, but that's mostly an aesthetic difference.
There is a difference in the ingredients, the ratio and quality of meat to other bits, etc. Please don't start the "what should actually go into sausages" thing again :C
(yeah I know but in a lot of cases it is the same stuff repackaged and the packaging - what it signifies to us and tells us about ourselves - is a big part of what/why we buy things)
As someone already hinted, it's not always exactly the same - they'll rate appearance and give deformed objects to the value/basics line, or use slight variations in ingredients (salt/etc) to cause differences in flavour/calories/etc.
It'll probably also vary between supermarkets as to which products are snob-traps.
Then what the hell are you still rabbitting on about?
All Spars around here are just oversized newsagents, and generally have a lousy selection of rubbishy foods. (Can't get decent cheese in them, for example.)