Catalytic Converter Estimate QnA

[PROW355]

After putting some decent mileage on the good ole X (currently at around 160,000) mileage, it has come time to have the catalytic converters (including both O2 sensors) replaced. I have recently received an estimate from a local indy who I am not familiar with and his estimate seemed a bit higher than I expected so I am hoping someone with experience with this type of repair could give me some feedback regarding the time required for labor and the price for parts.

NOTE: The price for the ignition issue repair and price is not of my concern. I am needing to have the key repaired or replaced. I think I might have the Scott at bmwgm5 repair it for a fraction what it would cost to replace it.

I have also noticed that I could purchase all of the necessary parts from Bavauto for less than half of the price of the OEM. Does anyone have any recommendations regarding the use of the bavauto aftermarket Catalytic converter and Bosch O2 sensors? Good or Bad experience with these parts?

Although this indy described above would not allow me to purchase the parts and have him put them on, I do know a guy who will do the job with the parts I provide.

Can anyone give me any insight into the dilemma of purchasing the OEM or Aftermarket Catalytic converters and if one or the either is better, worse, doable, etc? And if the estimate is reasonable for this job.

I have relied on everyone heres individual talents in the past. I respect everyones opinion/perspective on this matter and I would appreciate any help and or recommendations the forum can provide. TIA