Two years ago I had a good idea for a business. Something we had wanted to try for a while, so I alloted some cash for it. The name was a good one, and we wanted to use it. The first thing we did was make up the domain portfolio. That is, the list of site names that are closely related which we wanted to own. There were 15 variations of slightly different spellings and hyphenations and domains. All of them except the main .com we wanted were available and only $6. Made sense to buy those. All were redirected to that one main one. The main one cost us $800. I went to Sedo.com. They're a broker who makes heaps of money off of this sort of thing. They charged me $69 for the initial "estimate" of value. I'd call it a conflict of interest, since they made 10% on the sale of it, paid by me. That estimate was then accepted as the selling price by the owner, and I paid it. The owner had a WHOIS that was listed as the domain manager (1&1.com, I think), so I couldn't get to the owner directly. My feeling after the experience, besides feeling dirty and cheated, was that the process is set up as a pretty nasty racket, with many layers to make individual contact next to impossible, and really leaving little idea for the average person what the value of a domain is. That's the problem when the owners are just parking domains to make a profit. They aren't seeking to make the sale. The buyer is at an automatic disadvantage because there is an apparent and obvious need expressed simply by asking about it.
For those of you that are wondering, the domain I bought was tunersedge.com. We liked the name for an aftermarket performance auto parts retail site. Unfortunately, 2 years later, still no time to make it happen, but I still own the domains (all 15) and the company is still a legal entity. Maybe someday...
