Changing the order that the Blue Elves were placing that dramatically caused them to need to rebalance everything from their client list to the budget for this run. The Villa Stones would definitely sell well, but they didn't' know what regions would pay the most for them yet.
And until they knew that, there were risks involved that they didn't want to take too large of a loss on. So, they still needed some of the basic items they had come for, with the Villa Stones added.
The question was how many of them they needed.
If they added them to the order, they could likely make a huge profit off this run. But if they replaced the weapons, as Eryman wanted, they ran the risk of both getting a poor price, and running out of them too early in the trip.
That was part of the risk of being a Captain that nobody really talked about, but one of their most important tasks.
