Bonded currency.

[MagicManICT]

Well, coins CAN be melted back down into bars in a finery forge, so though you can't eat a coin, you can study it (depending on coin type and available curios, of course). What doesn't work with coins is the management system. It's horrid.

If you're looking for intra-village trade or a wage system, pick what you want as your standard. While a pearl is the global standard, there's nothing saying it has to be the ONLY form of trade.

Feel free to try coins. One of the villages in w3 worked with it for a while, but I can never remember who (and it was just mentioned elsewhere on the forums). Try digging around a bit for more commentary.

[Tonkyhonk]

Buyan market (Samarkand) in w3 worked fine with coins perfectly, but mining system was way different and metal production was pretty much limited to major towns back then. (invites only, many players from different areas used it.)
i think i heard RoK was using coin&tax system internally in w5, and worked as intended, but i didnt witness it myself. i remember one talking about steel price getting very low only internally because of that.
i used a barter stand in my own village in w5 <but only between 2> and i used dreams for currency (i always hated harvesting dreams, and having a big stock of dreams always helped.)

i think you could do a coin system internally if you can control mintage among your villagers. but it can be very vulnerable, and finding the balance and the rate may not be so easy. (one douche villager could ruin it easily.)

*edited for the wrong link.