LPT: Want cheap textbooks? Look for an 'International Edition' online for a fraction of the price

They will usually say something like 'Not for use in the United States' but they're generally fine.

Some of them are identical to the US edition, most of them just move a couple of chapters around. Same content, slightly different order.

Most of them will be printed on different paper and generally be of lower quality. If the US edition is hardcover, the international will usually be paperback.

They generally come with the same CDs or online codes as the US edition, but you should double check the listings or reviews.

You can find them mainly on Amazon or eBay for about a quarter of the US edition's price--although I've seen anywhere between half to a twentieth of the US price.