Whichever one you want to do really...
After doing a little more research on the subject, I found that Silver by weight hasn't really changed that much in relative value over thousands of years until the end of the 1800's. A day's of hard work, and 2-5 grams of silver paid was more than enough to buy a week worth of food. Then, silver mining exploded to the point that almost all of silver ever mined in human history was in the last hundred years. Before modern times, the value of silver didn't change much (though Rome is one example). Having one currency (as long as its a precious metal of some sort) is quite believable to have, and you wouldn't need inflation as a side mechanic unless you are making jumps through time that are less than a few years apart.
On the other side of things, we use paper and electronic fiat money today that isn't backed by gold. in earlier times, we switched between gold and silver, whichever was perceived as more valuable at that time. Earlier than that, we used whatever was shiny, such as copper, tin, or even shells. In the future, we might switch entirely to electronic credits and not have to ever carry around money. You don't need inflation for this either, because, if Silver can be worth the same through most of history, you now have an exchange rate that can be applied to every currency so they are always an equal value.
On point 2....magic (Ancient), alchemy (Medieval), science (Modern), ......space magic? (Future). There are at least a thousand ways to come up with an explanation for them all to have equal potency.
Whichever one you want to do really...
After doing a little more research on the subject, I found that Silver by weight hasn't really changed that much in relative value over thousands of years until the end of the 1800's. A day's of hard work, and 2-5 grams of silver paid was more than enough to buy a week worth of food. Then, silver mining exploded to the point that almost all of silver ever mined in human history was in the last hundred years. Before modern times, the value of silver didn't change much (though Rome is one example). Having one currency (as long as its a precious metal of some sort) is quite believable to have, and you wouldn't need inflation as a side mechanic unless you are making jumps through time that are less than a few years apart.
On the other side of things, we use paper and electronic fiat money today that isn't backed by gold. in earlier times, we switched between gold and silver, whichever was perceived as more valuable at that time. Earlier than that, we used whatever was shiny, such as copper, tin, or even shells. In the future, we might switch entirely to electronic credits and not have to ever carry around money. You don't need inflation for this either, because, if Silver can be worth the same through most of history, you now have an exchange rate that can be applied to every currency so they are always an equal value.
On point 2....magic (Ancient), alchemy (Medieval), science (Modern), ......space magic? (Future). There are at least a thousand ways to come up with an explanation for them all to have equal potency.