well, for this we would have to see the domain instead of the site
But, in general, domains that have nothing special about them sell for whatever the buyer's willing to pay, which is why - when in doubt - it's just best to let the market decide by auctioning the domain and selling it to the highest bidder.
If the domain is special, however (short, catchy, brandable, or any combination of these) it could sell for a good chunk. But again, the real value is hard to figure because it still depends on what the buyer's willing to spend, but I know from experience that 3-4 letter domains usually sell for 10s, or 100s of 1000s of $$$. So, if your domain is short (1-6 letters long I would say) you can probably bank hard on it, especially with those delicious stats. And speaking of stats...
Leaving the domain part aside, I think you can EASILY get upwards of $5000 for this site based on these stats. And if the backlinks are good (high authority, DF and / or coming from big players in that niche) you can double or triple the starting amount. At least that's my opinion, but I'm not a domain appraiser, so I don't know the exact value, I only spoke based on my past observations...
Also, my opinion is based on the assumption that your site is not losing rankings and / or traffic. If the ranked keywords, indexed pages, and / or traffic are on a downward trend and a potential (but knowledgeable) buyer sees this they might not be willing to pay even $5000. Just saying