2002 DC ADVENTURES OF SUPERMAN #600 NEWSSTAND VARIANT. SUPER SIZED ANNIVERSARY ISSUE WITH SUPERMAN HOLDING AMERICAN FLAG. RARE SUPER LOW CGC CENSUS OF ONLY 18 TOTAL ACROSS ALL GRADES AND THIS IS THE NEWSSTAND VARIANT. CGC GRADED 9.6 WHITE PAGES. ACTUAL ITEM IN PICTURES FOR SALE.

Comicbookinvest website has data showing that in 2002, newsstand variants only made up 2-5% of the total printed comic books on the market. 

Newsstand variants were not sold to collectors inside comic book retail stores. They were found at actual newsstands, often displayed in spinner racks inside liquor stores, grocery stores etc and were typically printed on lower quality paper and were never bagged and boarded and often abused. Very few newsstand variants survived making them extremely SCARCE in high grade and many unsold newsstand copies were either returned to the publisher or destroyed.