I've done web development for some larger premium dating sites in the past, and I know the amount of revenue which comes in through such sites is quite high. You'd be surprised at how much income can be generated from such a site, and although there is some higher algorithm development that needs to be done for a dating site for matchmaking, compared to physical product the overhead is fairly low once it's built. With this being said, if you can find the right end user, I think you can easily get $5k or more. Not to mention its a single word domain in a growing industry.
Personally, I'd recommend sitting on it and listing at around $10k + negotiable. Just my 0.02 based on my past experience.