Minor priceAbsolute, priceMultiplier, priceRelative are in OpenADR.
Current schema uses relativePrice & priceIncrease
Price Relative can be an increase or decrease.
Value associated with priceRelative is +/- value; Value associated with price Multiple is a multiplier.
The term Ratio is usually experessed with a quotient; it will only be one value in this case.
The should be an associated unit and currency specification. I am assuming this will be provided as used in the EI message, or will have to be added as part of this element.