I gave a similar thing a whirl some time back. The fee was around the same I think but the first few people to sign up got a big discount (I was one). The names that came back were a bit underwhelming. From what I can remember it was a bit [keyword]box.com, [keyword]hq.com, go[keyword].com etc etc. Stuff that implied not a lot of effort had been put into it.
Now, sometimes those domains work well, but I'd like a bit of variation and thought put into it. Not something I can unimaginatively test out myself in 2 minutes.
I believe there may be a service there, but it would require more than "here are five domains that I think are quality". You would need some sort of statistical analysis or metrics behind it. What are the advantages/disadvantages of choosing this domain over this one, what are the things that attract customers into being more likely to click on this domain vs that domain, etc...
Not to mention, that as things like Twitter get more and more popular domain names tend to get pushed more into shortened urls where domain name isn't shown.
I think it would probably be worth something, not sure about $100. But I see the biggest problem is trust. I would be afraid you would send me the top 3-12 instead of the top 1-10 that you found.
'Quality' is the issue, I agree. Especially with domains and branding, beauty is often in the eye of the beholder. What you think may be awesome may not appeal to everyone (or anyone!)
Now, sometimes those domains work well, but I'd like a bit of variation and thought put into it. Not something I can unimaginatively test out myself in 2 minutes.
However, for $100, is it worth your time?