An X-Men #1 CGC 9.6 has recently changed hands in a private sale for $200,000, a new record for this issue. The 1963 comic by Stan Lee and Jack Kirby introduced concepts which in the coming decades would become one of the most successful comic book franchises in the world. The original issue featured Professor Xavier and a team of Angel, Iceman, Beast, Cyclops, and Marvel Girl taking on Magneto.
This copy was sold by Metropolis Comics of NY, whose Comicconnect.com auction arm has set the pace for high end sales in recent times, such as with the $1.1 million sale of an Amazing Fantasy #15 earlier this year. Indeed, it's been an incredible year for high grade copies of vintage key Marvel comics with books such as Tales of Suspense #39, Avengers #4, and Incredible Hulk #181 all setting new records.
This particular X-Men #1 is widely known as the Mound City copy, having surfaced as part of an extensive original owner collection in the St. Louis area in 2009 and brought to market by Mound City Auctions.
Interestingly, this copy is not the highest graded example known — there are two copies graded higher at CGC 9.8. It's difficult to estimate what one of the 9.8's would bring if it were sold at this point, but with the way the market is going now, high six figures might not be out of the question.