in a nutshell, the price multiplier should be given a random maximum nominal limit of trade prices each villager, once the price of the trade reached the cap, no more multiplier could be applied, to prevent excessive algorithm or worsening the fairness when compared to the current version (Java 1.13.1).
i have found that the newer trading system will have a really tremendous change, which introduced the economic trading method. however, after taking a look into it, i found kinda unknown problem about it.
java edition 1.14, Bedrock 1.11 or more equivalent
what is it?
i mean, if you trade the same slot multiple times, the pricing of so will increase. however, this might mean that, the possibility of really high trading price. taking a farmer as an example, you wanna get an emerald with 26 potatoes, but now you would wish to trade 30 times, the result of the 30th trade would theoretically ask you 26 (1.05^29) = 107.02 (3SF) when you keep trading with the same slot.
if the next trade price of the same slot would continue to increase, then it would worsen the sourcing to players. i do know that the mechanic is to prevent someone indefinitely trade for infinite emeralds, unless this is common and result in game-breaking advantage, then i do not think this will really helpful towards the players not involved.
also, unless the price would decrease when they trade with different slot, otherwise it would still be unfair to players, comparing with 1.13.
what do i wish to suggest?
that is simple, have a price multiplier should have a cap of it, the trade price would not over a randomly set limit, each villager has different nominal cap, but the cap itself is permanent and would not change regardless.
for an example based on this suggestion:
i have two farmer villager. assuming that you are first beginning to trade with them.
you began to repeat trading potatoes assuming they both keeps the same trading, you found that the farmer A asked you 35 after a certain number of times, and 34 for farmer B and their prices stagnated from further multiplying.