For some people these prices are high. Let me explain why they're not.
The first-edition D&D game (and other early games, for all I know), established the weight of a gold coin as 1/10th of a pound (presumed avoirdupois, about 453 grams). This was convenient for calculating weight, but anyone with experience in numismatics knows that 45 grams would be a ridiculous weight for a coin in circulation. The South African Krugerrand, comparatively, weighs 33.93 grams. The gold Brittania weighs 31.103 grams (one troy ounce). Neither are used in circulation. They are bullion coins.
The British gold sovereign, on the other hand, weighs 7.98 grams, a little more than one quarter the Brittania. It would take nearly 57 of these to equal a D&D pound. The sovereign is no longer used as circulating currency now, and probably wasn't much between 1604 and 1816, so we couldn't call it a premier coin in Europe during the Middle Ages or Renaissance. A more common gold coin was the Venetian ducat - which in the 13th century averaged only 3.5 grams. That's about 13 ducats per old D&D gold coin, in weight.
I've settled on the gold content of my gold coins at 3.57 grams of gold. They're mixed with 3.43 grams of silver (the value of the silver being discounted by state law), making a coin in my world 7 grams in weight ~ the purity of which can be checked by magic, so there's no danger of the alloy being modified to cheapen the hard value of the coins. One benefit of a D&D world.
Comparing the gold in one of my gold coins (a.gp) with that of the old D&D system (d.gp), means that 1 d.gp = 12.69 a.gp.
The splinted mail above, listed at 473 g.p., is actually reasonable, the equivalent of 37.3 d.gp. on the old Player's Handbook equipment table. Looking at the Player's Handbook, I see splinted mail listed at 80 g.p. That would be more than a thousand in my system.
Moreover, it means that I technically give more than 12 x.p. per gold D&D coin ... except that I give considerable less gold than the old game did, as I like to keep my players poor.
Anyway, just food for thought. This post was inspired by a post I read on The Gaming Den, where the first poster noted, "We know that D&D prices for stuff in chunks of gold is nuts ..."
No, not really. Just the result of poor designers not doing their homework.