The Product Price is set to 0.00 Special is set to 20%
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The Product Priced by Attributes is set to YES
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The attribute prices are defined without the price prefix of +
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The Display Price is made up of the lowest attribute price from each Option Name group.
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If there had been a Product Price, this would have been added together to the lowest attributes price from each of the Option Name groups to make up the display price.
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The price prefix of the + is not used as we are not "adding" to the display price.
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The Colors attributes are, their prices before the Special discount is applied:<br />
White $499.99<br />
Black $519.00<br />
Blue $539.00
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The Specials Price is a flat $100 discount. This $100 discount is applied to all attributes marked attributes_discounted Yes.