If you add the prices in the bubble, you get 19.32. This was a big year for socialism, which saw the formation of the UK Socialist League, the Scottish Socialist party, the Socialist Republic of Chile (lasted about 90 days), the publication of Leon Trotsky's "Foundations of Socialism," and Hitler's view on Socialism published in Liberty magazine, among other events no doubt.
$18.09 is a suspicious price. Somebody is making a statement, though I'm not sure what. The meme itself, obviously is pointing out the hypocrisy of the shirt and it's price, but it seems like there is more to this.
