Why was the Shelish killed for merely expressing astonishment at the Nevu'ah?
Malbim: (a) The Navi spoke to the king. The Shelish should not have answered - especially since the king wanted to kill Elisha due to the hunger, and doubting the Nevu'ah for relief is like affirming that he should be killed. (b) The Nevu'ah could have been fulfilled naturally. This was the going price in Eretz Yisrael during the famine, just in Shomron prices had skyrocketed due to the siege. If the enemy would be removed, automatically the price would match that in the rest of Eretz Yisrael 1 ! (c) He doubted Hashem's ability - "Yad Hashem Tiktzar 2 " (Bamidbar 11:23)?! (d) He contradicted the Navi's word.
Above (7:1), Malbim said that this is a standard price during famine. Surely it can vary. What is his source that now, this was the price in Eretz Yisrael? Also, removing the enemy is a miracle! Also, the price should increase, for the supply did not change, and the demand increases (now, also Bnei Shomron will buy the grain)! And even if eventually the price will descend to that in the rest of Eretz Yisrael, on the first day that grain becomes available, starving people [who yesterday paid high prices for a donkey's head or dove excrement - 6:25] would offer more, in order to be among the first buyers! (PF)
One could say that he merely doubted that Hashem would do such miracles for idolaters. However, since he died for this, surely he was a Rasha, and we should judge him unfavorably. (PF)