Why doesn't RepairPal show an estimate for a rusted out muffler replacement?

Seems like many of the other repairs I viewed on this site have assumptions listed. It would be helpful to list the price range with the assumptions listed, so the VARIABLES are defined. For instance, the catalytic converter price range is huge and the assumptions and variables are defined. I appreciate that the site creators have at least put some range at the site for a catalytic converter replacement with the applicable assumptions.

You know what they say about assumption's though, and that is usually true! Especially in auto. repair. If we assume the rest of the exhaust system is ok, then you can buy a cheap muffler for an assumed price of 29.95. Then the shop might charge an assumed price of 30.00 to install it. On the other hand, you may need the entire exhaust system if the rust has consumed IT too. No way to tell until the work begins! However the catalytic converter is what it is and it has to meet certain criteria, so price is easier to estimate. The install of the converter is not as the parts list cannot be determined until it's looked at.The best thing to do is call a muffler shop and get a price, then shop around.