Dental Advice needed

[MS Fowler]

I have a mild tooth ache that comes and goes. It is never so severe that it keeps me from sleeping or eating. Ibuprophen removes the pain---for now.
I went to my Dentist, and he looked at it, and took an X ray. He gave me the film and wants me to see and Endodontist. My Dentists thinks it needs a root canal and a cap. He says there is a black spot at the tip of one of the roots.
His fee for a cap would be $950, and figure another $500 for the root canal. Thats $1500 that my dental plan does not cover, so its all out-of pocket.

The tooth in question is the next to last tooth on the lower, right side.

I am considering just having him pull it. The problem is, and what I need advice regarding from people who may have some experience is this--That would leave a single tooth, isolated at the rear of my mouth. Is that a problem just waiting to happen? Is that tooth more likely to break becasue it no longer has the support of a neighboring tooth. I am not worried about appearances--the tooth is too far back to be seen. But I do wonder if that isolated tooth might just be too distracting to live with.

Have any of you have this?
What other options might I have that I do not see?