I asked and got vague answers. I think he just knows he must be missing out on a better experience. He'd like a vintage one, actually. Got a source for that?
Answering this question first.
That's not a good idea. Hair has a shelf life and it's measured in years, not really decades. What he probably actually wants is a vintage handle with a new knot. All you need is to find the handle, drill out the old knot, and install a new one. If you don't want to do it yourself, there's a few people out there that will do it.
Answering the other questions. Full disclaimer, I do sell brushes. Boar is the cheapest and best bang for the dollar. It will soften up with use and a lot of people really don't see the point of badger if they love boar enough. Good quality badger is about 6-10x the price.
Moving up, you have clipped badger hair, usually mixed with goat hair. Basically leftover hair. This option is usually a few dollars more than boar. I don't use this hair.
Moving up, there's black badger/pure badger. It's a little scratchy, but it's basic badger.
Moving up again, fine/best/finest badger. Then silvertip, then exotic hairs.
Here's a hierarchy and description of most badger hair grades. The names change with supply/demand & customer expectations (aka every brand uses their own names).
http://wetshavingproducts.com/badger-brush-hair-grades/
