Bob,
It just takes a bit of work.
I've got a list of several hundred available domain names that I check daily to see if they are still available. If I had the bucks, I'd own every single one of them!
The key to the whole thing is really taking the time for research.
I see an awful lot of "junk" names up for sale for $5-$10 because folks just rushed off and registered something they "thought" was catchy. It wasn't, and now they want to dump 'em.
One guy came to me with a list of 24-names he wanted to sell ($5-$6 each). I can't even give 'em away ! They don't make sense, would probably never be searched for, and are a pure waste of money.
Then again, I've got domains listed on my portfolio site with prices ranging upwards of $250,000. The right buyer will probably pay that.. or more. It's just a matter of finding the buyer.
Research, research, research.
Pete