Paul Franklin wrote:

....
If it were only a few grand I'd walk away without a second thought.

The other lots on my short list are only 3 acres instead of 5 and the
asking prices are $15,000-25,000 *more*. And it's not just money..the
other lots are not as desireable in terms of our particular wants and
needs, although most might see them as more desirable...which is part
of why they are priced higher.
....

As I suspected, you've actually already made up your mind that this is
what you want and are looking for reasons/excuses to justify that
decision. I'd recommend proceeding very slowly. There's a fairly
obvious reason the other lots are priced as they are relative to this
one it appears.

Just a question--what are you going to be able to do on 5A you couldn't
on 3?