@plainoldme,
It was ridiculously expensive the last time I sent a book o/s by airmail, POM. As I recall, the postal charge was more than I paid for the book. Rather discouraging if one likes the idea of doing this often.
I got the surface mail idea from another A2Ker, who sent me her copy of
The Corrections tapes this way, a few years ago. (She was a firm believer of "once you've read it, pass it on". Or, in this case once she'd listened to it. Great idea, I thought.) It took a couple of months to get here, but it was well worth the wait.