David,
We are talking about antique handmades here not machine mades where just one tiny little scratch can drop the value. Even with "dings and hits" most of his marbles are well worth it. Yes, he has a few smaller mibs in there or even common one at that but we are talking about the average of the lot. You are right about one thing, a book cant put a price on most marbles because until it is in your hand it is just ink on a piece of paper (the same goes for Ebay). I was at the Vegas show where I was seeing peewee's (handmades) selling for hundreds of dollars. Now i would never pay that price but others will and i know for a fact that no price guide out there has 1/2in common swirls for that price but guess what, they sell... As far as the condition goes handmades are more lenient. I am not saying that a marble with multiple hit marks is going to grade mint but when you are talking about a 2in onionskin or swirl that is nice and wet but has a small half subsurface moon is going to degrade the marble down to near mint or place the value of the marble any less. Again, the value of the marble is just in the eye of the beholder.