I can't figure currently what I could ask for it.
Some domains can be appraised more easily than others. Maybe they fit with past sales. Or maybe they suggest obvious industries and business plans. Or maybe they're just junk. This domain isn't any of those things; so it's not that an appraisal is tricky so much as it is a case of an appraisal not really being very meaningful, practically speaking.
It's like this: Maybe someone will be interested enough in Yeppers.com to ask you for a price or make an offer. But that tells you literally nothing about their budget. And you'd have no way of knowing how focused they are on that one domain. Most likely they'd be interested in all sorts of names and just be considering Yeppers.com as an option. So if you push up against their budget much, then the average person will look for something cheaper. It's very unlikely that Yeppers.com will be the one domain somebody just can't imagine alternatives for.
You see what I mean?
So the appraisal for Yeppers.com is whatever you want to ask price-wise. Assume that you'll get maybe 1 inquiry per year. Most inquiries won't be serious enough to spend a lot or deal with aggressive negotiations. Basically, figure out what price you're comfortable saying "No" to and for how long.
I think low to mid $x,xxx would be possible for the ideal scenario of an end user with a substantial budget whose first choice brand name is "Yeppers". But how likely is that? Not very.