While there is a limitation on for how much a player can sell an item at Black Lion Traders at minimum (since with the merchant NPC that is the price), the similar limitation for the buyers does not exist. It makes it very annoying with low pricing sigils and runes that the buyers think that they could order the item for 17c, while nobody can sell it below 19c. This issue is blocking the market of the affected sigils. The minimum price should be introduced for the buyers as well.