Both Ryochan and sunflower have made good points, 
and my comment is along those lines.

When people resale they want to make a profit, 
whether it be a few dollars or ten times the 
purchase price. But the buck must stop somewhere 
because there comes a time when there is no one 
left who is willing to buy at your price. And 
there will be times when you bought something 
when the prices were high, but by the time you 
sell it, the demand is low so you can't recover 
your buy price. That's a fact of life, that not 
every non-consumable you buy you can sell again 
for a net gain.

---Trebuchet