Eh, I disagree. Golf clubs are a high margin item. There's also all of the assorted accessories, like personalized golf balls and golf shoes. There are some terrific merchants at cj.com and shareasale.com . Looking at it from the perspective of a merchant or an affiliate promoting for a merchant, the traffic that you get - though it might not be huge - will be very focussed. You won't be getting teenagers looking for free downloads, you'll be getting young to middle aged adults, fairly well off shoppers with credit cards.
The value in these types of domains, though, is not in the reselling, or parking, it's in the building. Msn and yahoo place a fairly large priority on the domain name when figuring ranking in their databases. One of my TOP income generating sites is a three word .us that has the word 'buy' in it: don't let anyone tell you it's not valuable, because I can vouch otherwise. I haven't touched that particular site in months, and it's generated aprox. 110 thousand visitors over the last couple of years.
Had I not developed a small site, and just parked it, it might have generated 20 people a month, if I was lucky. It's all in how you focus your time, just buy and park, or buy and develop.
Undeveloped, I'd say reg fee to most people here. Developed with some traffic, and backlinks, mid xxx, more depending on your success.