The 6.1 takes 7qts 0W40 synthetic oil, not cheap oil anywhere you buy it,plus the filter and labor.
Put anything else in it and the engine has trouble and Mopar will not warranty any repair.They will want lof receipts and can have the oil checked at a lab for type.I just retired from a dealer and have seen and been thru all of this,100 bucks is right in line for that engine.
Just my 2c worth