Ya I would say $30 each or a little higher. Depends on the domain sig1.com sig2.com. etc I would pay more for same with sex1.com, etc.
I think thier are only a few that are really good. If you had a business name with 3 letters and 1 number it would be great but most have more than that and do not use numbers often.
I don't know. I've been holding on to INK6 for ages. I thought a tattoo company, or artist would eat it up, but it ain't selling. It will someday. If it is snazzy, and you can get a good price. I would get it. Depends on the Real Estate. Location is everything
It just really depends on who thought about it. If something thought about your domain while you still have it yeah that would be great for you. But you know alot of times they proably think about it right when you decide to drop it.