You really need a basket of things that reflect comparable purchases. Hard to do over 100 years with so much innovation during that time.
On the other hand I suppose that the consumer price index is considering the same basic goods and services such as food items, transportation, basic medical care, housing, etc. I suppose that the statistic is not that subjective since changes in the basics have been rather insignificant .. an egg is still an eg, a lb of sugar the same, even a bus ticket as a basic form of transportation is desired within affordability regardless of whether the buss had a 8.0 liter engine back then or is electrical now days. What I am trying to say is that 0.25 in today's money, while it may have a slight variance, still makes for a nice and affordable pipe. A dr. Grabow nowadays starts at $60 and some change .. In my opinion, the only difference between now and the 1920 in this regard, is a huge gap in demand - less demand, the prices for pipes skyrocketed.