Not sure if there are affiliate programmes for haunted hotels but that might be an idea.
It's a nice name that folk would be willing to pay a decent amount for, not sure how much.
Why did you buy the domain? The reasons you bought the domain for should give you a good idea as to how valued the domain is; the more reasons you can think of the higher the value. People who may want to buy the domain will be thinking the same reasons I'm sure. According to Google keyword tool, the term 'haunted' gets searched approx. 9,900 times every month so there must be something to that.
With regards to the search results for any keyword term, the fewer there are, the more chance you have of getting ranked high. Doesn't really have much bearing on value I wouldn't think but to resellers, the fewer search results the better.