It's about time for me to quit the Science Fiction Book Club again. Let me explain. I periodically join the SFBC, buy out my freedom from the book requirement, quit and then later join up again, all so that I can get those wonderful bonuses for joining. You see, I love the SFBC, but it certainly does make it easier when they give you six free books.
Here's the downside. You had better like hardback books. If you keep your books and want a pretty decent standard, then a book club makes sense. I read many books strictly in paperback because they are the intellectual equivalent of toilet paper. Disposable. However, when it comes to collecting decent omnibuses, collection, special editions, art books, the SFBC is the place to go.
Also, the SFBC send you a monthly list of books that IT WILL SEND YOU, and you had better want them because they make it difficult to return anything. If you don't want any of those books, which I inevitably wouldn't shake my ten foot pole at for a nickel, then you have to send the form back at your expense and in a timely fashion, 'cause those books will be in your mailbox faster than you can say, "Oh no, not another book about cute teenage vampires."
There's away around it. SFBC has a website from which you can decline the monthly selections without penalty. The website also makes it really easy to find out what books they have.
Now, here's the good part. If you're careful and you stay away from the Anne McAffrey omnibus, you can actually get a pretty good deal off the hardback books. Spend any time in a used book store and you'll quickly see the piles of SFBC books that silly people have bought and found are not worth their shelf space. Don't buy those books, no matter how mcuh money the SFBC says you will save. And don't be afraid, when they say you get five free books, to trade in two of those free books for one really super duper nice one. I almost always pick up a copy of Spectrum, a really classy annual fantasy and science fiction art book. They almost always offer a bonus choice, you get a free pewter figure, tote bag or t-shirt, or an additional book. Take the book. That's what a SFBC is for. Keep your eye on the prize.
Stay away from the gazillions of flash in the pan titles that are better read in paperback at a quarter of the price. Instead, check out the SFBC's wonderful set of special collections, where they have reprinted true SF&F classics in matching slipcovers. Those are really cool, and will bring back fond memories of your explorations in SF when you were a kid and picked up your first Heinlein or Asimov.
The bargain bin is a good place to save money, nearly as good as a used book store. I have a great fondness for their non-fiction SF books, especially those concerned with writing and world-building.
Although book clubs in general are to be avoided like a gorn with PMS, the SFBC is very possibly an exception. It is still a book club, and you shouldn't join unless you are absolutely positive that you want to buy hard back books at hard back prices. Otherwise, stick with Amazon and you local independent book-seller. Please, do not become a Barnes and Nobles trollop.