From the Power Grid - Korea map rules :
Phase 3 : Buying Resources
In reverse player order, each player chooses one of the two markets from which he will buy resources this round. He must buy all resources for the round from the market he chooses. If the market chosen has no more of a resource he wants, he will not be able to buy that resource this round.
Note : All of the following actions would be done in reverse turn order.
Case 1 : Do all players choose, each in turn, a market and then, all players, again each in turn, buy their resources?
Case 2 : Do all players choose a market and immediately buy their resources from that merket before the next player chooses a market and buys resources?
The reason for my question stems from the aformentioned rule :
If the market chosen has no more of a resource he wants, he will not be able to buy that resource this round.
One has to admit that a reasonable player would not choose to buy from an empty market.
The only justification I can find for this rule is the following :
A non-empty market becomes empty after the player has selected it.
The only way for that to happen is that the previous player has bought all the remaining resources.
That could reasonably only happen in Case 1.