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.

The OE converter should be around 1K. If the aftermarker converter should be much cheaper.

Make sure that you get a good quality converters. Otherwises, it will break easily.

You may find the OE used one from wrecking shop. It should costs cheaper.

I would check to see if they are under warranty . I don't know about HK , but in the US we have a federal law that goes beyond the MBZ warranty period. I have called MBZ direct and had them instruct my dealer to replace at no cost when I had a rattle in my cats.