Dwindling MPG

I have been noticing I have been getting worsening mpg on every fill up. Hand calculating of course. So I decided to take a look at air filter. Filter was extremely dirty so I ordered a new one and replaced it. Went is Mann OEM filter. I also had some debris on the filter leading to MAF, I cleaned that out. Then took her for a drive and noticed a difference, seems like the motor can breath now. My question is I am thinking of replacing the MAF sensor, should I buy the OEM sensor or try the Bosch for $13 cheaper? I feel inclined to spend extra for OEM since Audi is a sensitive car.

OEM is the usual way to go with these things. But if you aren't having trouble with it leave it alone. No need to replace it if it isn't causing issues.