Most sellers are reasonable. I look any book over very hard when I receive them and compare with the notes and pictures. If in worse condition than led on you are very protected through ebay and paypal, just ask for a partial refund or return it. Don't leave negative feedback unless they won't work with you, this is how a lot of these guys earn a living.
That book would benefit from a pressing. Some research and a $150 t-shirt press will make a big difference, yes a t-shirt press works very well. I press my own books (probably 300-400 by now) and these older books press out very well, new books are harder and you need to be careful with the staple pressing through to the cover. But it is not hard at all, just a bit of a learning curve. Practice on the .50 bin for awhile, you will save a ton of money. Books need to be humidified first too, that is what makes all the difference. Make a humidity chamber, costs all of $20. I have turned 8.0 books into 9.6 - 9.8s, sometimes takes 4 or 5 presses that most won't do for you though.