Money is fairly inconsistent. If you compare tria to dollars, sometimes a tria seems to be worth about a dollar, other times a dime or 10 dollars. Quests give rewards to make the quest worth doing, and charge amounts to set the difficulty of the quest, without regard for an underlying economy. A few circles may be a months wages for some and pocket change for others, but if that is the case there should only be a few wealthy characters. Below are a few examples, and there are many more.
10 dollar trias.
In one quest we learn that a sunshine squadron guard makes 2100 tria in 6 months, or 350 a month. In another quest we learn that a sunshine squadron guard makes 4200 a year, or 420 tria a month, unless Roobelh uses a 12 month calendar. A winch guard apparently makes the same or less, because one who was transfered complains about it. Note also that one winch guard who sides in the Arena got 2 Trepor hearts in a night, which sells for almost a months wages. Why keep the day job?
Food is very cheap, costing a few tria. Food is about the only thing a guard could afford.
Potions probably fall into this category, although it is hard to judge magical substances.
1 dollar trias.
Weapon prices fall roughly here. Some rare flowers cost about 20 tria each. Sending a message to the bronze doors costs 20 tria. Beverages cost much more than food, and seem to fit more in this category. A kitchen knife is 50 tria.
Raw materials seem to be priced here. I hope a gold ingot is enough to make 2 golden circles, and so has a slightly lower value. That would make sense.
10 cent trias.
A certain Kran appears to consider 2 diamonds as a snack. If 10 diamonds was a days food, that Kran would eat 320000 tria worth of diamonds a year. Diamonds cost 100 tria, 10 months of 32 days. That is an expensive diet. Maybe Kran only eat a full meal once a month, but it seems to be implied that Kran eat as often as others. Maybe add some text saying he hadn't eaten in weeks and felt a bit peckish.
A leather apron costs 200 trias, although there are extenuating circumstances. And a waitress can afford that with only some hesitation. If a waitress was on the same tria scale as a guard, that would probably be a months wages.
Candle wax costs 100 trias. Ink and paper costs 50 trias. A blank book costs 100 trias. Paper appears fairly common as notes and receipts are bandied about in lots of quests without concern, but when you go to buy some it is suddenly a rare commodity. Either use wooden nickels in place of paper notes, or acknowledge that paper is common.
The taxes that people owe indicate that a tria is not worth much. And the tasks performed to get people to pay taxes indicate little concern for what would be 10 years wages to a guard.
Jewelry probably falls here, as an unadorned golden ring just isn't worth that much.
Other things.
Some quests refer to disparate prices for goods in different areas, but all the goods that players trade have equal value everywhere. With the exception that in some quests you get a one time offer of some highly inflated amount.
Diamonds sell for much more than other crystals. In RL diamonds have a wider variety of industrial uses, and there is probably some artificial inflation of diamond jewelry. Is there a diamond cartel in Yliakum too? Why are diamonds worth 100 times as much as rubies? Maybe diamonds are much more magically potent or something, but they are equally difficult to mine.
