AbeBooks is very hit or miss when it comes to buying books from their numerous books sellers. I have orderd two out of print books from them with no problems yet other people seem to bash this site a lot. Why? Because they don't do their research before purchasing a book. So here are things you need to look out for,
1. Look at the sellers reviews and ratings.
2. Do not buy from sellers that use stock images and have a very vague description of the book itself, these are nearly always scams. Buy from book sellers that use their own photos, if they don't see if they have a very descriptive review of the book itself.
3. If you have no choice but to buy from a seller on AbeBooks that uses a stock photo and has a very vague description, email them and ask about the condition and if a tracking number will be supplied. If the seller responds in a short time and provides you these answers then you should be safe to go ahead and purchase it. If they don't, avoid buying from them as most likely it is a scam.
What you have to know,
Don't be stupid, do your research!