Author here, AMA
$19.95 + shipping and handling is a bargain. Charge more!
(The programming world has been waiting a long time for a Billy Mays of devs. You're a natural.)
The video was fun, catchy and engaging. You explanation was clear and concise.
The music was fine at the start but as it continued all the way through it made it hard for me to concentrate and I found it easier to mute and use subtitles.
Definitely all in on clojure now (well, I also like zig)
Since I wanted them printed using real screen printing, we only had one shot to put in an order that was big enough.
But tell you what, give me a contact email and I'll send you a spare that I have (if "large" works)