After using several trades with a couple villagers, trades I use frequently have increased in cost and other trades have decreased. However, the GUI does not change to show these changes in costs, but instead stays the same and gets a little buggy when trying to trade.
For example:
Paper is 24 per emerald, but in reality it is upwards of 30 but still says 24. When attempting to use less than 30, it will keep reverting the trade until it says no more trades are available but reopening the GUI will undo that.
An enchanted book is 9 emeralds and 1 book, but when trading it takes only 6 emeralds and 1 book and returns 3.
Related issues
duplicates
Attachments
Comments
migrated
migrated
I have this issue and then some. Not only do displayed prices not match the actual costs, but also the trading progress bar does not increase, even after high level trades. See attached screenshots of before and after trading with a villager. Before, there is no progress bar, and glowstone costs 4 emerald. After, I have spent 3 emerald, and the progress bar has not gone up.
violine1101
This has been fixed in 1.14.4, see MC-151282.