2018 MARKET UPDATE: NEW ENTRY ON THIS YEAR'S HOT 100!
It's pretty rare that a low-volume turnover Silver Age comic book makes it to the 100 hot comics list. But this book keeps heating up, so it's time to bring it to your attention.
Given that Superman movies have been around since the early 80s (much earlier than that, if you count the 1953 movie), there are plenty of super-villains who have already been 'cracked open' in the DC Cinematic Universe.
Brainiac is not one of them (see also Bizarro in Superboy #68 for another we fancy). Added to that, this book is VERY frequently missing from collections we buy from this period. Action Comics #252 (first Supergirl) is much more common.
Record sales are easy when a book has been under-valued for as long as this one has.
It's an especially tough find in higher grade, with that dark purple cover showing wear very easily.
The slightest crease will pop out of the cover of Action Comics #242, because that deep purple color is one of the worst for showing damage.
Given that it's over 60 years old, finding a solid one is tough. A CGC 4.0 of Showcase #4 will cost you 20 times as much as this book (crazy!). That book is relatively OVER-valued, but AC #242 is definitely one that has plenty of upside potential.
Brainiac is definitely NOT the Flash. That said, you could see him being a foil to the oh-so-serious DC Cinematic Universe rendition of Superman. He's one of the historical comic book super villain names that has yet to be attached to a future movie treatment.
Prices jump pretty quickly once you get above FN (CGC 6.0). If you can afford it, go for a 5.0, which is only about a thousand bucks more than a 4.0, but much harder to find.