I'd cast the net a wee bit wider and carry out a search on Biblio.com which links you with small, private booksellers world-wide and their stocks.
I have picked up quite a few books via Biblo that were either as scarce as hen's teeth (and therefore horendously expensive via Abe or Amazon), or else unavaliable, yet when I went looking on Biblo, I not only found numerous copies of the book I was looking for, but often found a good-condition copy at a much cheaper price.