The traffic from the old websites will likely die off eventually, which means it's not much of a factor.
If the name is generic it might also be getting natural type ins, but that's hard to say without seeing your names.
If the names are generic, or look like a good brandable made up word, or a name that could be a good name for a business, it might have value beyond just the traffic. I'd like at dnjournal.com sales reports and see the lists of sold names, that should give you a good comparison.