Of course, I'd never purchase a bag intending to sell it, but I end up giving some as gifts or trading them, because I live in apartments with a few thousand books. (You put two readers together, both studying Shakespeare . . . you get more bookcases than dishes.) I love my Tom Bihn bags! But, despite their act as Hermione's magic purse, they do not fit in one's hand, and there comes a time when I have to make some hard decisions about which bags I'm actually using and going to use in the near future.
I have a "Tom Bihn" search saved on eBay, I get an email each day with new bags listed for sale. (I also have searches saved for specific editions of books I want, it keeps me from spending too much time on eBay.)