As long as they're nice confusing multiples; pounds, shillings, pence type of thing rather than this newfangled decimalised malarky.
Not exactly what you meant, but I remember I think it was AD&D (1st Edition), it went something like: 10 Coppers = 1 Silver, 10 Silver = 1 Electrum, 20 Silver or 2 Electrum (less common) = 1 Gold, 5 Gold = 1 Platinum.
Funny thing, I'm actually allergic to Platinum. I break out bad, I feel like I have a million ants crawling on me, and I get all confused.

I'm all for Copper, Silver, Gold, and Platinum in game.