I created it as a new calculate column. My current DAX formula is as follows and works perfectly but again I get ties for any vendors with the same amount of rows (transactions) and I need to break this tie:

IF(AND(Data[Vendor Number]<>BLANK(),Data[Filter_12_Weeks]="within prev 12 weeks"),RANKX (ALLSELECTED ( Data[Vendor Number]),CALCULATE (COUNTROWS ( Data),ALLEXCEPT ( Data,Data[Vendor Number], Data[Filter_12_Weeks])),,DESC,Dense))

What I need is to somehow incorporate a sum of the [QTY] column for each [Vendor Number]. It should rank first by the count of rows per [Vendor Number] and per each[Filter_12_Weeks] as it does in the above formula, but secondly by the highest sum of [QTY] per each [Vendor Number] and [Filter_12_Weeks]. This should break ties and give me a true ranking. Make sense?