Some things that I've never liked in most RPGs, both Pen and Paper and online is the lack of a sense of real economy in the game. In most games, starter items have a trivial cost compared to enchanted items, and even these grow at an exponential rate. The cost these items are such that typically games at hire level deal in a form of currency that is not even known at early stages in the game, where at the same time typical currencies cease to have any value.
Toward the beginnings of a character's career, items are tracked down to the copper piece, soon, copper and silver are not worth bending over to pick. Items in town some become more money that the whole town used to have, and characters buying items with enough gold (if divided equally) would allow them all to take a year off, and not do anything.
I just want a economy system that makes a little sense, where supply and demand mean something as do a silver and a copper. The system I'm aiming for essentially factors into the value of the raw material, workmanship and time to determine an items value, an items don't just get a factor of 10 or 100 applied to them because they are magical.
I know ancient coins had a lot of odd conversion between one another, and I don't think I need that amount of realism. After all I don't think the players are coming to the session for a math lesson or to balance their characters finances.
So for coin value, I think metric currency makes a lot of sense...10cp = 1sp, 10sp = 1gp, 10gp = 1pp. Someone can argue the actual alloy make-up of the coins to get such a system to make sense as far as the raw value of such items are not metric.
In addition to this I think if players think in terms of actual currency for value of these...say a copper is worth 50 cents...then a Silver is about $5 and a gold is worth $50. Doing so make coming up with a drink costing 1sp or 2sp for something some nice easy to imagine, or when the barkeep says Elven wine is 10gp a glass that is some expensive some, at about $2500 per bottle.
In doing so, you can easily imaging what a laborer might make, say 1sp per hour, or 1gp per day might be reasonable for non-skilled work. A foreman type may be 2 to 4 gp per day...which equates to about $200 a day.
A shop owner likely makes a decent living, especially if they are skilled labor with apprentices (who typically work for only room and board, and possibly menial spending money), with the owner doing about $500 to $2500 a day in income, so from 10gp to 50gp per day. Granted they still have raw material cost and shop fees, possibly licencing and taxes to deal with.
But with this thinking you can begin to put things into perspective, a typical riding horse may cost $1,000 to $5,000 dollar or 20gp to 100gp...War trained animals would be much higher, based on the rarity of the creature...but comparing these to vehicle prices now-a-days would likely be comparable...I trained rare mount my go for $60,000 to $100,000 or 1,200gp to 2,000gp.
Dwellings can bought for current housing prices as well...a place to "hang the armor", using a trailer park as an example may cost $25,000 to $50,000 or 500gp to 1,000gp...where as a small keep and a good plot may be in the $5,000,000 or higher range, that's 100,000gp or more.
Sticking would converted or roughly equivalent modern prices allow for players to immediately equate a quality items or rip offs, rather in most fantasy systems the exponential cost growth as level increase, really gives them little appreciate for actual item value.
That said the going price for getting a mercenary (a.k.a. a Hero) to risk their life might be $1,000/day (20gp) or more if the risk is known to them...The employer may try to sell the party on "keeping the loot they find"...but that offer only goes so far, if there's a Ancient Dragon known to have the item it its hoard. Though the party could be tasked with negotiating with the Dragon for the item, if the price is right.