Secondhand online bookseller USA?

[Desiderata]

I want to send a copy of a book I enjoyed to a friend in the US. I was going to post my old copy out, but realised it would probably be cheaper to buy one online and get it posted to his address instead.
I usually use World of Books in the UK, but looking for recommendations for a similar US site (that I can order from from the UK.

[Yertis]

AbeBooks

[Mortarboard]

Yertis said:

AbeBooks

This is the way.

M.