@jojojaybartering is process is very realistic. I don't see removing such nice element from game is reasonable. The system can use a few improvements and most of it work fine.
Modern city person hate bartering because they are lazy and used to stupid ripoff prices marked by the seller where they can secure a great profit over basic costs that is impossible for any primary sector able to make by bartering.
Current system is just trade with basic price: if you balanced two side you got the deal
which is very generous and ideal to player(customer) and they don't ask anything above that for profit
also you can sell back anything at their full price
if we are going to change the trading mechanics, considering they are selling the excess things from villages and players are the one who asks, the bartering system should favor villagers and we should pay more to get the deal
@Rhaikh introduction of production and need is a nice suggestion and quite common in trading/merchant sim but I think this doesn't very suit the game
you won't see many professional traders spending their time and taking risks traveling in cold dangerous wild of iron age Finland, even they do they are no going to make great profits as most villages should be self sufficient in order to survive in this environment
two exception will be salt and iron, which is already portrayed by foreign traders
using reputation in trading is not actually implemented but the basics are already in game
there are some reputation levels about trading from 'cheater' to 'fine tradesman'
they don't do anything and 3 negative levels are unobtainable because you can never make a trade where village side have losses
they might have actual influence in future versions