Quoted from Dkjimbo:
Everyone here is "guilty" of flipping for profit. Its essential to participating in this hobby at all short of independent wealth and life financial circumstances not attainable by most people. In fact some here have turned it into a primary source of income. It can still be a hobby while profiting at the same time. Most just sink the profit back into the hobby but its still profiteering no matter how you look at it.
Speak for yourself. I know a lot of people who probably lose money on every game they buy.