Even if the official Mongolian warhorses selected for tribute trade flow into the Inner Border, they can be sold for 20-30 taels immediately, but the court's prescribed tribute price remains unchanged. 25 horses for one iron pot, take it or leave it, the tribes are eager to trade!
As for the manufacturing cost of a large iron pot within the Inner Border, it's capped at 5 taels of silver. 25 Mongolian horses can fetch at least 500 taels. This enormous 100-fold profit, even if the major share goes to the border army and officials, the life-threatening risk is still enticing for civilian households and merchants to take the risk!
