1990 Mercedes Benz 300e muffler

Engine Mechanical problem
1990 Mercedes Benz 300e 6 cyl Two Wheel Drive Automatic 158.25 miles

The rear muffler broke loose from one of the suspension points and torqued, breaking off the exhaust pipe on inlet side. I need a new muffler and my mechanic's price for the part (from his supplier) is $480.

Searching on the web, I see ANSA mufflers for my model at a more reasonable $158. Are these OK to use? They claim back pressure etc. Are the same.