My first recommendation is always to try your library. Interlibrary loan is incredibly reasonable (.50 to 1.00 most places.) Borrowing a book gives one ample time to decide if it's really going to be of enduring value. When buying books, I prefer to shop at independent bookstores, but my main consideration is their ability to order books, convenience, and courtesy of staff. If a local store can't get the book by the time you need it, feel free to try the publisher. The reviews include the publisher's web link and phone number where I have it, and always the publisher's name and location - one call to directory assistance and you've got their number. Publishers offer a variety of shipping options, from book post to almost instantaneous. Many feng shui books have made their way to used bookstores. If you're not already a used-book shopper, you may be missing out. Feng shui books are not famous for being cheap. Also, if a book is less than you'd hoped for, you can always sell it back to them. Good used bookstores are treasures in any community. If you've go one--support it. Reuse is the second of the three basic R's of ecology.
Occasionally I recommend books that are out of print. Two excellent sources for out-of-print books are www.abe.com and www.bookfinder.com