Item 93058 was a 1892-O $10 MS-61 CAC with a mintage of 28,688, and hammered for $1800 plus fees. Item 93060 was a 1893-O $10 MS-61 CAC with a mintage of 17,000, and hammered for $1500 plus fees. Both appear very similar with marks, etc. So, as a newbie gold collector, I wonder why would the lower mintage coin hammer for several hundred less. Please make sense of this for me?