The Dover reprint of the English version of the book is not particularly expensive. I paid $15 for it in 1996, and the last time I looked it was still on their list, although the price has crept up a little.

The Dover edition, or at least the one I have, is the "Second English Translation," revised and updated to the Fourth (last) 1877 German edition, and does contain lots of footnotes that probably weren't in the original(s).

It is, indeed, the "classic" treatment of the physics of musical tone production. Although it's not particularly technical, including only elementary math, this is NOT A BOOK (IMO) to tackle in a language with which one is not fairly fluent. (i.e., IT'S REALLY BIG).

One of my favorites, and frequently consulted.

John