French in Action
Textbook - Third Edition - Part II
The third edition of the French in Action Textbook is published in two volumes: Part I and Part II (whereas the first and second editions encompassed Parts I and II in one volume each). As with Part I, the third edition of Part II of the French in Action Textbook will likely be the easiest edition to buy in new condition from a large book retailer. Meanwhile, you may expect to not find it as easily as the older editions from a used purveyor.
This edition has some incremental material compared to the older editions, but I do not think the extra content is critically important. It includes some extraneous distractions (e.g. Marie-Laure's Twitter feed) that dilute the 1980's purity of the original product. For this reason, I prefer the second edition books. But these third edition materials appear to lack nothing of the earlier editions, so they are great for self study.
For the money, if all you can find used is the second edition, I would buy that. Meanwhile, shop around; the new price for this book will sometimes vary among these popular retailers: