Over the past couple of week, copies of Shazam #1 (1973) have been moving off eBay at a good clip and for over the $1 price they had been previously selling for.
The question is, why? Maybe it has to do with the Comicbook.com article the came out at the end of April. According to the article the Rock, who was previously speculated to be in a Lobo movie, is now rumored to be in a Shazam movie.
Now this is not the first appearance of Captain Marvel, that happened years before, but this is when he was brought into the DC universe.
Also on the move is Shazam #28 (1977), the first DC appearance of Black Adam. These are definitely worth keeping an eye out for.