I utilize what I call steak-based economy on my server. I figure grilled steak is pretty much the most basic staple, so I go on the assumption the effort to craft a stack of grilled steaks (including farming materials and the crafting itself) approximately equivalent to the effort involved to mint one gold coin. As such a stack of grilled steak is worth one gold coin. For items other than steak, I just extrapolate the effort required in comparison to estimate a rough value. I use bronze coins as placeholders in our bank for 1000 gold coins, and 100 silver coins is worth one gold coin.