@dalehileman,
I am no economist but it is pretty obvious than "inflation" cannot simply be exemplified by the cost of postage. All prices are subject to supply and demand, and the price of mail is sensitive to the decline in paper communications due to text and email.
What actually matters,( in Western economies at least), is whether expectations in in living standards are maintained or are declining. Inflation is part of the complex mechanism involved in those expectations, in which
deflation can also be problematic.