What single purchase has returned the most in terms of value?

I got one of the fancy ones, but yeah, I can’t ever go back to TP now.

This one is even more financially beneficial than most people realize. Besides using less TP; a bidet also lessens risks of hemorrhoids and urinary tract infections. This can save you tens of thousands of dollars (if you're in the USA) on surgeries, doctors visits, labwork, and antibiotics.