"very clean link profile" doesn't mean too much when assessing the value of a domain.
It's more important to know the number and quality of the RDs and their backlinks. If the RDs are decent you can add $0.5-1 per RD to the final price of the domain. And good RDs (BBC, Cosmopolitan, etc) can add way more than $1 to the price, and if you have 150 such RDs you can add at least $400-500 to the final price which, by the way, in the absence of quality RDs and backlinks will mostly depend on the monthly revenue and traffic, as well as the niche and brandability of the domain.
Your niche is ok, a very tough and profitable one, and since you manage to get 8k visitors a month I would say you can sell this domain for a few $1000s easily... if it's a good domain I mean. If it's a long-ass domain like mikestevenspersonaltrainingsite.com ... well, not very many people will be willing to pay you handsomely despite of how good your site is. The brandability and catchiness of a domain name are very important. If it's a short domain, though (up to 10-12 letters long, but preferably 5-8 letters long) and when combined with the great niche, great traffic, great RDs + backlinks and (hopefully) great revenue... you can easily charge upwards of $10k for this domain because you'll be selling it as a business at that point.
Take a look at flippa, empireflippers, and the alikes to see what prices sites like yours are sold for, you can get great inspiration from such marketplaces.
