Yes, want vs. need is also a good point. Going to Africa and charging $20 for a bottle of clean water is ethically wrong IMO, because it's something a person needs to survive and be healthy, part of the basic human rights we all share. Or price gouging during/after a hurricane. It's taking advantage of people's misfortune and desperation.
You don't need a lipo to survive and be happy (some here might argue otherwise
), so I don't see any ethical obligation to limit the price. Look at diamonds, one of the biggest shams of all time; make the supply artificially scarce, a few monopolies controlling the market, but you can't really get too upset over it because no one really needs diamonds (some wives/girlfriends might argue otherwise). If you are willing to pay exorbitant prices for a luxury item, so be it.
Damn, I'm getting way too philosophical about some overpriced Turnigy packs on Ebay...