…on eBay. Wow, Wonder Woman doesn’t garner as much as fanfare as Superman’s 1938 Action Comics #1 that saved a family from foreclosure or the 1940’s Batman #1 that also just hit the auction block.
eBay has a few Sensation Comics #1 for sale. A restored version, with a 9.4 NM CGC rating, has a buy it now of over $18,000.
There’s about a month still left on that eBay auction, so you have time to find the money. That auction can be found here.
