By “an original Batman comic book ” I assume he means Detective Comics #27, Batman’s first appearance, though that doesn’t really make sense to me.
Now, if he’s said he had a six-pack of toilet paper… well, actually still not.
Is the fact that this was published three days before St. Patricks’s Day relevant? The bat at the end of the rainbow???
Comics I Don't Understand 
That original comic book is worth as much as a pot of gold? Maybe?
what DNH said
To the colorist: It’s Roy G. Biv, not Roy G. Bir.
@beckoningchasm, if you’re going to nitpick the rainbow you have to mention that they always appear exactly opposite the sun.
The comic represents ‘The pot of gold at the end of the rainbow.’ If.that is, you’re familiar with the phrase.
Even if the rainbow hues are hopelessly wrong (cyan?), I think it‘s a refreshing change that Deering bothered to color his work at all. The last three “Strange Brew” comics we’ve seen here were just covered over with an annoying pastel filler (which is a pretty clear indication that Deering is responsible; a syndicate flunky would get fired for such nonsense).
It’s because Batman and Robin are gay. https://slate.com/culture/2016/04/the-history-of-the-gay-subtext-of-batman-and-robin.html
Yes, it’s the pot of gold. I’m bothered by “an original Batman comic book.” I own lots of those. Why didn’t he say “the first Batman”?
Because comic strips always get details about comic books wrong, unless the strip is written by a manor comic-book aficionado. And Batiuk just does ‘OK Boomer’ references to ‘Silver Age’ comics, anyway.