Counting people as a repugnant transaction

This week's Torah portion, Ki Tissa (Exodus 30:11-34:35) has some well known parts (the Golden Calf and the civil war that followed when Moses returned; you shouldn't boil a kid in its mother's milk...), but it starts with a census. And the census is described as follows (JTS translation)

"When you take a census of the Israelite people according to their enrollment, each shall pay the Lord a ransom for himself on being enrolled, that no plague may come upon them through their being enrolled."

The "ransom" is described as a half shekel.  You could read this as a tax.  But the Rabbinical commentaries expand on this in a number of ways, and one of them says that while it's ok to count coins, it isn't ok to count people, since a person can't/shouldn't be reduced to a number.

This makes census taking a very unusual repugnant transaction. Many non-repugnant transactions are rendered repugnant by adding money (think of kidney donation, which is almost universally applauded, versus kidney sales, which are widely illegal). Census taking is one of the rare examples of a repugnant transaction rendered non-repugnant by adding money, and counting the coins.