John Bidwell recorded some prices in his entry for July 25, 1841.
I will not omit to state the prices of several kinds of mountain goods. Powder which is sold by the cupful (pint) is worth $1 per cup. Lead 1.50 per lb., good Mackinaw blankets 8 to 15 dollars; sugar $1 per cupful; pepper $1 also; cotton and calico shirts from 3 to 5$; rifles from 30 to 60. In return, you will receive dressed deerskins at $3, pants made of deerskins $10, beaver skins $10, moccasins $1; flour sold in the Mts. at 50 cents per cupful, tobacco at $2 per lb., butcher knives from 1 to 3$. A good gun is worth as much as a horse; a cap lock is preferred, caps worth $1 per box.
These prices would have shocked the folks back home. For comparison, here are a few prices in Massachusetts in 1841, from Comparative Wages, Prices and Cost of Living (1885) which contains prices going back to the 1790s.
White sugar sold for 15 cents a pound (and there are several cups in a pound), flour sold for 4 cents a pound, or $7 a barrel, and pepper was 20 cents a pound. A blanket cost $5.50 but whether it was a “good Mackinaw blanket” I don’t know.
Pocket knives were 25 cents each; a butcher knife would have cost somewhat more, maybe 50 cents. Tobacco was 20 to 28 cents a pound, so you can see that the price had increased 8-fold in the mountains.
This must be where John Bidwell acquired the “buckskin suit” he mentions wearing when he and Jimmy John went to get some snow from the mountains.