I have a 2000 E320 and need to replace both left and right catalyt converters. I found it about $430 per piece from online store. But according to the search result on cat converter people mentioned that replacement cost for both converters are around $2500. This confused me on how come both parts only worth $860 but the final bill is 25k. Is it a lot of labor to get this job done. Is it a DIY job.

My car is a right-wheel car and most of those parts online places are from US, do i need different cat converters for my car.

Thanks for your advice...

Joe