You know, if you want to sell some old 501's, simply wear them while running around in Europe. I've worn 501's pretty much all my life, and when I was in France in the mid 80's, people kept coming up to me and offering to buy my jeans because they were faded and the main reason, they were Levi 501's.
I also remember another time when I was a Harley rider and I was approached by another dude who told me he liked my leather jacket. Well, it was around 8 years old by this time and had seen a LOT of miles on my motorcycle. When he asked me if he could buy it, I asked why, and he said that he liked the road worn way it looked and offered me 300 bucks for it.
I told him to go buy his own jacket and do some riding, because mine wasn't for sale.