I spend much more time focused on acquiring good domain names than selling them. I might make one or two efforts to sell domain names each week, but I am sending perhaps dozens of purchase offers each week for significant amounts of money.
At this point in time, nearly all of the best (one and some two word .com) domain names that are unused are in very strong hands. In many cases, the owners have turned down serious offers over the years. Some of these owners include Fortune 100 companies, well-funded startups, and other entities that don’t have a desire or need to sell any domain name assets unless they are blown away by an offer.