2014 I bought 8 pounds H4350 $176 + shipping

Today that would cost $370 + shipping

[$370/$176]^-10 = 1.077 -> 7.7% interest compounded annually.

There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. -Ernest Hemingway
The man who makes no mistakes does not usually make anything.-- Edward John Phelps