For what it's worth.

[the 'stache]

Interesting question, Jon.

In order to determine a fair price, I'd use Card Target, and for any cards not appearing there, I'd look at the recent sale history on Ebay.

For somebody not familiar with the hobby, I'd take as much time as necessary to walk him through each card. I'd show him the results of my research, and ask for his input. I'd then make a fair offer.

I'd be curious about the history of the collection. If he knows nothing about the hobby, how did he come to have them?

Since they are a personal collection, I'd likely keep them for myself. I'm sure they'd have a nice resale value, but some cards are meant to be kept together.

The bottom line, though, is that I would treat him with respect.