Wealth Management
Character wealth is a common problem in games. Being poor can be inconvenient for the characters and frustrating for some players, but is rarely problematic for the GM.
Characters getting "too rich" on the other hand can pose issues. How do you manage PC wealth?
Level-Based Wealth Abstraction
Generally, currencies are the province of individual settings. If you want to bypass all of that you can just make every purchase of significance a roll. Apply losses as a special Hindrance on the character's liquidity; it won't affect them for other rolls, but they lose purchasing power until they address the Hindrance in the fiction somehow.
This will generally mean making money by hiring out for jobs or looting treasure, but could also imply a line of credit, or even just a significant reputation that makes the locals charge lower prices for them. Walking into a saloon and hearing the bartender cheerily quip Your money's no good here, mate! while pouring you a tall lager is sometimes as good or better than actual coin.
This implicitly links their purchasing power to their Level, which isn't entirely crazy, but has some side effects that may seem odd. A Level 3 PC with no Role at all won't have the purchasing power of a same-Level Performer with haggling-relevant Maneuvers, but that's more a matter of the smooth-talker getting more for their money. Level drives everything in Level One. It makes a certain amount of sense that a character with more worldliness and reputation might also have more wealth.
Also, always remember that you shouldn't bother to roll for things that aren't really consequential and interesting. New characters may struggle to afford a beer, but well-established heroes won't quibble over the price of the better wine with their meal. If they have a Big Spender Hook, maybe they find out when it's time to pay that they don't have enough after all!
You never have to do it this way, though.
Barter
The well-established and "universally valued" currencies of grand empires are historically tools of rich urban areas. Out in the fringes where characters often start there will be towns and villages, but they deal often as not in direct trade of goods and services for goods and services in return. How many eggs you get for a rabbit skin depends on the quality of the skin, and how bad the chicken farmer needs it, and how many eggs he has… This is ideal for setting up simple quests. Where a low level character might agree to bring three more rabbit skins for a dozen pickled eggs, higher level characters would be asked for basilisk venom to tan the most supple leather, and be offered Silent Boots in trade.
Don't fall into the modern mindset that any price is fixed. Merchants charge what they can, and everyone haggles. Your gold florins are good in Foriccia, but a merchant in Gerschtalt will eye them with suspicion, bite them, weigh them, and offer less than he really thinks they are worth, purely on the local market of gold. Most of the wealth characters find shouldn't be money anyway: portable loot will more often be jewelry, vaults will have unwieldy treasures like bullion and artworks, and real wealth is land.
Traditional Currency Tracking
There's nothing wrong with counting coin if that's your preference. Currency standards were invented for a reason, and cities, guilds, and trading companies all work together to ensure consistency and validity. Measured monetary units are extremely useful in cities, and if your game is going to be low-wealth for the foreseeable future then coins are a great treasure for characters to find. Just remember that prices change.
Don't fall into the trap of making every shopkeep sell the same candle for the same three "silver pieces" and have it always last the same two hours. It's fine to track details, but one sure way to sell a medieval-style fantasy setting is to bring home the inconsistencies.
There should be things you don't "just buy" because money alone isn't enough. You want shops with powerful magic swords on racks with pricetags, we're not here to tell you that you can't, but it devalues the wonder of such items. Try at least to make sure there's a story that goes along with each item. If someone offers to sell you magic there should be a story, a quest, and a cost beside just changing the balance in the character's bank ledger.