Priced By Attributes
To use the 'priced by attributes' option, the price on the main product page should be left blank and all prices are set in the attributes controller as whole values without a plus or minus sign.
So if you're converting existing product listings to be priced by attributes, you have to remove the price from the main product page and then edit the prices for all of the attributes to the actual price of each attribute.
If you have a bag of food priced at $5 for sm, $15 for med, $25 for Lg, your settings are as follows:
If it's NOT Priced By attributes:
Price on main product page is $5 (equal to the smallest option).
If it IS Priced By Attributes
Price on main product page is blank or removed