I think you have already spent more in renewals than it is worth. Not much search volume for this exact phrase. Reseller value low XX. If you haven't had an end user offer in 10 years, unlikely you will ever get one. Develop it or let it go.
Standard Appraisal Thread Disclaimer:
My appraisals are based upon years of following the market and participating in the domain business. This is a subjective business and you may sell any particular name for much more than the appraisal value, or you may never sell it. If my estimation is obviously in error, someone else will likely post a different appraisal. If you argue, whine, cry or complain, I will not appraise any more of your domains. I am one of the few people willing to waste my own time doing it and be the first to post an appraisal because of the tendency of OP's to flame low appraisals (which applies to most of them).