Japanese to English Bus/Financial Management

Hi,

I have come across this term in a document concerning the drop of production at a company's plant following an accident at a raw material supplier's plant.
The document states that 変動費利益単価 is calculated by 販売単価から変動費単価を差し引いて算出する. Assuming that 販売単価 is unit selling price and 変動費単価 is unit variable cost, what would be a suitable translation for 変動費利益単価?
This term did not return any hits on search engines.

Thank you in advance for any help.