[Bram99]

It’s an interesting question.

I have not seen a rule or guide as to how to do it but here’s the way I think the market works when it is efficient (when it has enough supply and demand to support regular sales on a given card).

I look at the card and make my own determination of the grade. Then I use the PSA/PWCC/VCP data on the card to come to a market price for that card in that grade (the grade that I believe the card is. My experience is that many sellers who will use “book value” in referring to a price guide will neglect to remember that the top book for a vintage card is roughly equivalent to a card in NM-Mt or “8” condition. So if they talk in discount to book, their discount may actually be a premium to the value of the card in that grade. Some sellers will want to wish the card is a better grade than it actually is. I almost always wish my cards are better than they are, and I am an infrequent seller.

Almost any seller selling a good number of raw vintage cards will know that a graded example of the same card in the same grade as a raw example should command a premium vs. the raw card due either to:
1. the relative certainty of the actual slabbed card grade vs the raw card where you don’t know what the TPG will grade it as, or
2. Simply the cost of grading the card at a TPG.

For one or both of these reasons, I apply an “uncertainty” or “grading cost” discount to the value in VCP.

The amount of discount could be anywhere from nothing on a low value common card to 1/4 or 1/3 of the VCP for a more expensive card.

I have become especially suspect of sellers who have high dollar stars that they are selling raw, especially if they have a mix of graded and raw. To me buying the high value card raw is too much of a risk for my tastes. The cynical conclusion i tend to make is that if the high dollar raw card were really high grade , that seller would be wiser to have it graded.

This is just one view from a long-time buyer/collector.

Tony