In general, I think those kind of domains will sell for anything around $200. If they're holding it for a sale, they'll probably want more, like $500 or more.
If they've used an anonymous registrar, you can check the domainwhois sites for a history if you really want, and contact old owners of the domains, it might still be them, but otherwise I'd say forget it - they probably don't want to sell.
My guess is that when I was blogging regularly it got enough traffic to get on some watchlist and when it became available was snapped up. But don't think it will see any traffic without me pushing it.
But I suspect you're right they don't make it easy to contact them so I don't imagine it's up for sale.