At or near the million $ mark, I suspect that a book being the "highest CGC graded" is not that big a factor when other un-certified high grade copies are known to exist. For example, I don't think Hariri was ignorant of the MH Action 1 when he bought the two 9.0 Action 1s. I am sure he (and his advisor Fishler) knew that they were, as you put it, "tied for second." He wasn't paying for the "best copy," he was paying for the "best available copy" (in his case twice) for the foreseeable future. Same was true for the buyers of the CA 9.4 and the AS 8 9.4. Other high grade copies are known, but those were the best available for the foreseeable future. The value of the 9.4 CA 1 would not be greater if the Allentown still remained ungraded, so long as the Allentown was still regarded as the "best known" (which it was long before it was graded).