Of course, it's hard to see NGG and the others like her mark the shoes (we want so badly) up by so much. She's got the in, and takes advantage of it. And legally, I can't complain. But it can be frustrating.
On the other hand...like you Fashion, I have recently started acquiring a small number of sale shoes (to sell) to fund my own bank-breaking shoe habit. I try to be picky about what I buy, only buying the styles & sizes that I think are good finds. And, I don't buy shoes out from under my fellow tPFers. Meaning, if I know someone is looking for something, I will tell them about it or post it on the HTF list, rather that scoop it up for resale.
I think if you are a good seller, who treats your buyers kindly and don't rob them with outrageous prices, it can be good for everyone.
I know I would not have found some of my favorite shoes without eBay sellers.