That price is waaaay too high.
Adsit, Timevalve, or WorldPac have direct replacements.
I know many members have had great experiences with Timevalve. If you do a search on timevalve, you can see all of the great testimonials, and they make them out of stainless steel. You should be able to buy the cat and exhaust (one long piece) for around $800.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".