Charisma isn't bugged, what it does is: If an item is lower than average it reduces the cost of it, if an item is above average it increase the cost. Therefore there is more profit per trading run you do. (Note: the average price is the mean price across all islands.) Ship buying is bugged though because you do need the origonal price of the ship to buy it, even though you do get the carisma discount.
 "Age Of Wind 2"){kind=icon}
 "Caravaneer"){kind=icon}
 "Elona Shooter"){kind=icon}
 "Frontier"){kind=icon}
 "Hedgehog Launch 2"){kind=icon}
 "Protector III"){kind=icon}