Can you tell me which is more valuable?

Hey, quick question here. I'm looking to flip a good niche domain, but I'm wondering which is considered more valuable to a potential buyer in regards to SEO, AdWords and authority through owning a keyword rich domain. Income and website aside, which domain would be considered more valuable (and help me to get a better price).

So lets say I have 'book.com' and 'books.com'

Book (keyword) has roughly 2000 exact searches a month, 22,000 broad.
Competition Medium.

Books (keyword) has roughly 750 exact searches a month, 8000 broad.
Competition High.


So clearly 'books' has less searches and is more competitive, but to a potential buyer would books.com be more valuable than book.com??

Appreciate some opinions.

A potential buyer is going to check the amount of searches before buying the domain, so 'Book' would be indeed more valuable.

But 'books.com' would be able to rank easier for both keywords 'book' and 'books', than book.com ranking for 'books'.

I would presume?

Still, with this in mind would you say book.com is most valuable?