I think you need a summary report. Such a report can list each account in two groups (loyalty program members and those that are not members) with a sub total for each. It can also just list the two sub totals.
Define a calculation field, cLoyaltyMember as: Not IsEmpty ( YourDropDownMenuFieldHere ). Select Number as the result type. It will return a 1 in the field if the client is a member of a loyalty program and a zero if the client is not.
On a list view layout, you can add a Sub summary layout part "When Sorted by" cLoyaltyMember. If you place summary fields that total your cost and sale price fields in this sub summary part, you'll get a sub total for each group. Put the same fields in a header, footer or grand summary layout part and you'll get a grand total.
The final requirement on this layout is that your records must be sorted by cLoyaltyMember or the sub summary layout parts will not be visible.