Commenting here, since the moderators of original post referenced didn't seem to understand this issue.
Orig post:

Right now, if I offer a $10 month-to-month price with a 10% discount for annual payment, WHMCS *should but does not* display the price as $9/mo. Instead, it displays "starting at $10" to the prospective buyer. This seems completely backwards. "Starting at" the highest monthly rate seems counter-intuitive to basic principles of persuasion.

Monthly: 10/mo = 120/yr <--WHY SHOW THIS AS "Starting at..."
Annually: 9/mo = 108/yr <--SHOW THIS PRICE BY DEFAULT INSTEAD