Inlaid chips as we know them were only invented around the 1940's. Those historic prices are almost certainly for hot-stamps or even blanks. Burt Co. did not sell hot-stamped chips, they only ever supplied blanks for distributors to stamp themselves.
Some 'naturally occurring' ingredients are no doubt scarcer now than they were back then. Another factor is that until 20 years ago, all pigment (which pound for pound is by far the most expensive ingredient) contained lead. I suggest that the R&D to find substitute pigment ingredients over the last 20 years ago is reflected in the current prices.
Ingredient prices alone make little difference to the final cost though, labor and utilities comprise 80%+ of the cost of a finished chip (unless an awful lot of material is lost to wastage in the early stages of production).
I always assumed the H & C in H C Edwards were Mr Edwards initials but I've yet to find anything to indicate that or otherwise.
You're right, of course. All those early chips selling for $8 per 100 were solid blanks.
I'm also thinking of "real" inflation, compared to the U.S. Consumer Price index. The CPI was changed in the 1990s, and is a pretty poor reflection of the real increases in the cost of good and labor. The latest incarnation of the "basket" of goods used to calculate the CPI always shows an increase of 2 or 3 percent per year. Using the "old" basket, it's closer to about 10 percent per year, suggesting that those 1929 chips were closer to $2 each in today's dollars.