Avid Reader asked below in the comments what the difference was. IMO - here are the basics.
1 - Purpose
The ARC's purpose is to be read by a reviewer or bookseller to create buzz about an upcoming release.
The second hand book is being sold after (often well after) the release date by a reader who has already paid full price for it.
2 - Money
If an ARC is sold - neither the author or publisher get any money from the sale.
If a second hand book is sold, the author and publisher have already made the money on it from the first sale.
3 - Implied Trust
An ARC is given to a reviewer in exchange for a review. If this abuse keeps happening, the publishers will stop sending ARCs and then all of us decent reviewers will miss out.
A second hand book belongs to the reader that bought it - they can then do whatever they want with it. The author hasn't trusted them to do anything but buy it. They don't even have to read it.
In a perfect world for authors - there would be no second hand books either, but ultimately they realise that the word of mouth from buying a book second hand can work and grow them new fans.
...and no - the NOT FOR SALE isn't on there because it's uncorrected. It's on there for the reasons stated above, because it is NOT a book - it's a printed out manuscript, a sneak peak for certain priviledged people before it goes on sale.