I've gotten quotes for replacing the catalytic converters on my Subaru and Honda and both quotes were over $1000.
Why is a catalytic converter so expensive? on 2000 Honda Odyssey
Some have a platinium-iridium catalyst which accounts for a lot of the cost.
2 more answers
basicly, it is all the precious metals that make it so wxpensive.
The catalytic converter contains a very expensive metal that cost more than gold.