We want our customers to be able to select a premium material and then add a fixed percentage to the product price. It seems we should be able to fix this using rate type pricing rules, but I cannot get it to function. Any suggestions?
You can indeed use the rate sku pricing in the pricing matrix.
You need to make sure that the multiplied rate has a Priority.
This way it is multiplied on top of the original SKU pricing.
Please let us know if this information was helpfull and you were able to add the rate type pricing