Posted By:
Jim VBSpeaking in generalities, a qualifier usually lowers a grade about 2 notches in terms of price (e.g.- a PSA 7 (MK) sells at about the same as a PSA 5 with no qualifiers. ) SGC does not use qualifiers, but in most cases they would give it 2 grades lower.
In the case of your card, I'll guess SGC would have called it a 10.
I have found the best pricing reference source to be vintagecardprices.com. He tracks all graded cards, from all sets, from Ebay and most major auction houses. He has about 2-3 years of history.
VCP usually lists all grades with qualifiers in the "Authentic" section of their listings.
Edited to add- Bobby types faster than I do. He is more succinct than I am. He is also the owner of VCP and far too modest to suggest you use his site as it is fee based (not free.)