[kirykl]

Replace it with a 33 cent coin

[grues-dinner]

I remembered there was some kind of "more efficient" coin system. I searched for "ternary coins" and "radix coins". Both are some crypto scams. Fun times.

Apparently I misremembered how it worked and it's actually 1, 5, 18 and 25 (or 29) for a 4 coin system: https://cs.uwaterloo.ca/~shallit/Papers/change2.pdf

[euroderf]

Replace pennies, nickels, and dimes with a 12 1/2 cent coin. Eight to the dollar.

[rahimnathwani]

When I was a kid, a first-class stamp in the UK was 12.5 pence.