I think you're confusing some of the timing here. Organized kamikaze attacks came much later in the war--in October of 1944 to be precise. The attack on Pearl Harbor was conventional in nature, featuring level bombers, dive bombers, and torpedo attacks. The torpedoes were modified to be able to run in the narrow depths of the harbor, but there were not mass attacks of planes crashing into boats in the 1941 assault. The Japanese lost well under 100 men, and only 29 planes. In exchange, the Americans lost over two thousand men, and over a dozen ships destroyed or damaged, including a number of battleships. Four battleships were sunk, California and West Virginia were eventually repaired. The Navy lost 92 aircraft destroyed, and the Army lost another 77 destroyed. The full list of American material losses can be found here.

In purely military terms, trading 29 aircraft and a couple small submarines for the heavy American losses can only be seen as cost-effective, to use your terms.