Must the merchant deliver three tons of iron at the agreed-upon price, without increase, even if the market price rises, knowing that it was not sorted at the time of the agreement but was available to him?

The sale was concluded by offer and acceptance, and possession is not a condition for the validity of selling iron. As long as the sale has been concluded, the failure to take possession of the commodity or transfer it does not give the seller the right to increase the price—even if the market price increases—just as the buyer does not have the right to decrease the price—even if the market price decreases.