> Barter economies never had inflationary periods.

Barter economies have also never existed in human societies. They have either been gift economies (esp. with smaller tribes) or credit economies (records dating back to the earliest tables from Mesopotamia and Ancient Egypt). See:

* https://en.wikipedia.org/wiki/Debt:_The_First_5000_Years

For a more recent example of a society becoming pure credit, see:

* https://en.wikipedia.org/wiki/Irish_bank_strikes_(1966–1976)

* https://www.youtube.com/watch?v=mFIQWWt4UaA

Barter economies also make it next to impossible to save for the the future. Most goods produced by common are perishable and therefore one cannot be “saved” in any meaningful way. This keeps people at sustenance level and working until they die.