They were completely earnest. The joke followed that they can't take money with them when they die, but they can take tattoos. Pharaohs still have their tattoos, they point out.

There is also a general pattern of spending "extra" money on things like parties, experiences, consumables, etc. Better to spend the money on a pizza party and gocart trip for their kids than to stash it away in a savings account. Better to spend the money on beer for a party than even to hide it under their mattress.