I don't mind occasionally being asked to mooch a second book to make it "worthwhile" for the sender to send to France, but today I drew the line at being asked to mooch four books, and therefore spending 16 points, in order to get one I wanted.
A quick check on Amazon France shows me that I could get that wishlisted book for 3 euros with postage.
It would probably cost me 2 euros to send that book back out internationally once I relist it on BM, the cost to me for that book seems to already work out at 5 euros.