Trade Prices

Trading

Price formula	Price = base price + demand increase - reputation discount - Hero of the Village discount. The result is kept between 1 and one full stack of the item.
Item that changes	Only the first item a trade asks for changes in amount. A second required item, such as the Book in an Enchanted Book trade, always keeps its listed amount.
Price multiplier	Every trade has a multiplier that scales its demand increase and its reputation discount. It is 0.05 for most trades and 0.2 mainly for armor, tools, weapons, maps and Enchanted Books.
Demand increase	Base price x demand x multiplier, rounded down, and never less than 0. A 20 Wheat trade with demand 16 and multiplier 0.05 costs 20 + 16 = 36 Wheat.
Reputation discount	Reputation x multiplier, rounded down, comes off the price. Reputation 125 takes 6 off a trade with multiplier 0.05 and 25 off a trade with multiplier 0.2.
Bad reputation	Negative reputation raises the price by the same rule. Reputation -25 adds 2 to a trade with multiplier 0.05 and 5 to a trade with multiplier 0.2.
Hero of the Village discount	30% of the base price at level I, rounded down, and at least 1. At level I a 10 Emerald trade costs 7 Emeralds and a 1 Emerald trade stays at 1.
Higher Hero levels	Each level above I adds 6.25%: 36.25% at level II, 42.5% at III, 48.75% at IV and 55% at V. A 20 Emerald trade costs 14, 13, 12, 11 and 9 Emeralds at levels I to V.
Prices per player	Prices are worked out for the player who opens the trading screen, from that player's reputation and Hero of the Village effect. Two players can see different prices at the same villager.