Divided by four, right, so $12k? I would think the medical, rehab, lost wages/productivity, and disability costs of an average table saw hand injury would easily exceed $12k.

It is not that simple. Replacing a saw is a loss to the business owner, while an employee losing a finger by his own fault costs nothing to the company.

Apparently you've never heard of this thing called worker's compensation.

Fortunately, or unfortunately, depending on how you look at it, this is not true. If you are injured at the workplace while performing your work duties and you are not actively intoxicated on drugs or alcohol, then you are entitled to medical care and worker's compensation for that injury. It is absolutely something that has a cost to the company.

This is both factually incorrect and not funny at all.

In addition, last I checked, modern medicine cannot reattach nerves so you lose a great deal of functionality of your finger or hand even if you save it.

See: https://youtu.be/Xc-lIs8VNIc?t=1095

I hope I am simply missing the joke if someone would be so kind as to clue me in.

Yeah, you're missing the joke. The joke is the US healthcare system and how expensive it is.

A sense of humor might cost in excess of a finger reattachment, though.