There are actually 27 volumes in the complete set of Time-Life's
Foods of the World set, issued in the 1970s, which was one of several different sets the publisher has issued over the years. Each title has an accompanying spiral-bound soft cover recipe book, and there are four supplemental volumes and a rare 3-ring recipe binder for a total of 59 books in a truly complete set.
Here are the titles and authors:
African Cooking by Laurens van der Post
American Cooking by Dale Brown
American Cooking : Creole and Acadian by Peter S. Feibleman
American Cooking : The Eastern Heartland by Jose Wilson
American Cooking : The Great West by Jonathan Leonard Norton
American Cooking : The Melting Pot by James Shenton, Angelo Pellegrini, Dale Brown, Israel Shenker, Peter Wood
American Cooking : New England by Jonathan Norton Leonard
American Cooking : The Northwest by Dale Brown
American Cooking : Southern Style by Eugene Walter
Cooking of the British Isles by Adrian Bailey
Cooking of the Caribbean Islands by Linda Wolfe
Cooking of China by Emily Hahn
Classic French Cooking by Craig Claiborne, Pierre Franey
Cooking of Provincial France by M.F.K. Fisher
Cooking of Germany by Nika Standen Hazelton
Cooking of India by Santha Rama Rau
Cooking of Italy by Waverly Root
Cooking of Japan by Rafael Steinberg
Latin American Cooking by Jonathan Norton Leonard
Middle Eastern Cooking by Harry G. Nickles
Pacific-Southeast Asian Cooking by Rafael Steinberg
Quintet of Cuisines by Michael and Frances Field
Russian Cooking by Helen and George Papashvly
Cooking of Scandinavia by Dale Brown
Cooking of Spain and Portugal Peter S. Feibleman
Cooking of Vienna's Empire by Joseph Wechsberg
Wines and Spirits by Alec Waugh
Supplements:
Menu Guide & Recipe Index
Supplement Number One
Supplement Number Two
Kitchen Guide
3-Ring Recipe Binder
The individual books are not particularly sought after by collectors because they're pretty common, but a complete set can fetch over $200 on eBay. The dealer of used cookbooks whom my wife and I rely on,
Janet Jarvits, charges up to $395 for a complete set in very good condition.
It's hard to find a complete set because the books were usually sold by mail, one book every two months, and buyers could return the ones they didn't want. It's also hard to find the books in good condition because the bindings were not the best and often the spines are torn, or they're very faded from exposure to light.