Yes, I love the sound they make and there is something very cool about controlling an analog display with software. I would love to make one, but this seems beyond my DIY skillset. I wish you could buy them for a reasonable price, but I couldn't find anything less than 3K (Vestaboard).

Projects like these are what push me to expand my DIY skillset. (I enjoy making things so much I want everyone to share my passion, not feel DIY is beyond them.)

Sure, the guy has some fancy tools, but what I saw looked like something you could have laser-cut by way of Shapeko (or similar online laser-cutting services). He in fact referenced an acrylic version that would laser up nicely.

I suppose the electronics would be a learning curve but I might just go with the KiCad PCB he provides and go from there. (Curious though about the acrylic version — how it handles the electronics.)

Vinyl cut letters... This is do-able but also points out to me that the author is something of a perfectionist. Someone just getting their feet wet in a split-flap display might start out lettering their flaps with a Sharpie.

As you say, if the fun is in driving an analog display with software you could do a lot worse starting out with matte board, hot glue, a Sharpie and a handful of electronics.