1) In comparison to the Real World, how much gold do you think is in circulation in Tamriel? Keeping in mind that the ONLY coin in circulation is made of gold. Also keep in mind that Tamriel is only just ONE continent which is at most just 1/4 of the planet's landmass. In TRW, there are, on average, 1,522.21 kg produced from mining. That's 3,110.42 pounds, or a little over just 1 1/2 tons produced in the entire world. Per year. From that amount there is not only coins created, but also jewelry, ornamentation for lavish buildings, crowns and the like, etc. Now even if ALL of that gold went into currency, how many could be produced? Well, how much would the average gold coin (septim) weigh? Well, figure that from one gold ingot you can make TWO gold rings, each worth 75 septims, so at most a septim of gold = 1/150th of an ingot. (No value assigned to jewelry-making craftsmanship.) How much does a gold ring weigh? The average man's plain wedding band is @ 10 grams. If that 10 grams = 75 septims, each coin would weigh only .0133333_ grams. There are @453.6 grams to the pound. [Times 2 to get the weight of a gold ingot = 20 grams. Those are some really small, teenie, tiny, minuscule ingots there.] 3,110.42 pounds at 453.6 grams per pound = 14,108,865.5 grams. Divide that by .01333333 and you get 105,816,752.9 coins from the total planetary production of gold. (Nothing diverted from coin production.)
Now, as Dragonborn gathering wealth at every opportunity, amassing 2 million septims in just currency in just ONE year is entirely doable. Or approximately 2% of the entire planet's coin production, by just ONE person. Now add the value of all the weapons, armor, artifacts, real estate, etc., et al, and that can easily make the value of the DB's annual income to be @10% of the planet's entire gold production.
Now factor in the incomes and wealth generation of the entire population of Tamriel to get a rough idea of just how many coins will be needed to keep the continental Economy clicking away. How much does a Jarl make per year? How much for the Emperor? How much do you think Erikur http://uesp.net/wiki/Skyrim:Erikur makes each year? All the merchants of not just Skyrim, but also all of Tamriel's provinces as well.
That's A LOT of coins needed to keep the Economy going. How many might that be? A billion? Not enough by far. A trillion? Probably still not enough. Whatever comes after trillions, getting closer. Per year. (LOTS of shrinkage as quite a bit gets put away in hoards, Treasuries, and tombs.)
Not enough gold enough in a planet to supply the needs of an Economy like Tamriel's.
2) You are talking about Supply-side Economics: "If you make it, someone, somewhere WILL buy it." That theory holds up about as well as "Trickle Down Economics". That is having only a laughable relationship to Reality.