So I finally found a used SOBDM at a junk yard in WY for $210 (plus $185 freight to Atlanta). The OEM part lists for $3990, but it is out of stock. Needless to say, I'm much happier with the price on the used part.
The donor car is a 2015 FFE with 36K miles, while mine is a 2013 with 67K miles...