want to create split valuation for trading materials purchased from different vendors

hi,

I want to create a split valuation for a trading material. The material will be procured from two different vendors. So I want to create split valuation based on vendor for trading material. And also I want to sell the above material with different rates (i.e. rate of the material x purchased from vendor a is having one rate and purchased from vendor b will be having one rate). Please tell the whole scenario.

Kindly give suggestions

regards

padma