The bookseller known as ProQuo Books on some sites and International Books on Amazon is a seller to be avoided like the plague. There are several complaints about this seller here, as well as on other sites, but none of those complaints mention the scam they tried to pull on me - FIVE times. International will list books on Amazon in "New" condition. Then you will get an email from them telling you due to "server problems" the book was listed incorrectly. They will tell you the book they have is actually in a lesser used condition and will offer to either refund you or send you the used book at a "discount". However, if you check a website like www.isbn.nu you will see the book is being sold on another site at a price considerably cheaper than International's "discount".
It's called a "Bait and Switch" and it is illegal in most states. International lures in a customer by being the cheapest seller of a New book on Amazon, which of course they don't have. Once you buy the book they send you the "server error" email hoping you bite. If you do they pull the switch by buying the book on the other site while having that seller ship it to you direct while they pocket the difference between your "discount" and the price they actually pay for the book.
What happened with me was I had bought a book, received the "server error" email and actually agreed to the switch, not realizing what was going on. When it happened a second time I thought "that sounds familiar" but still hadn't caught on. When it happened a third time the light bulbs went off. I compared all three emails and found they were word for word the same. I fired off an email to International and told them I did not like the looks of what was going on. I told them I bought a new book and wanted a new book. They canceled the order without so much as a courtesy email.
Some months later I bought another New book from International and got the exact same email yet again. This time I filed a formal complaint with Amazon who also never responded. International sells huge amounts of books on Amazon and I am sure Amazon did not want to mess with the commission they get.
When it happened a fifth time I filed a complaint with the Maryland Attorney General, who also did not respond! I don't know if the Bait and Switch is illegal in Maryland or not but I found it curious I got no response.
So, if you buy a New book from International or ProQuo books, and you get an email telling you about server problems - or if they want to make a switch of any kind - just be aware you are getting ripped off.