Different expense value during multiple GRN

Dear Experts,

We will be receiving items from vendor in different shipments. For each shipment the expense value changes and vendor Cost + expense should be loaded to inventory after GRN.

Example: PO created for item A.

Item A Quantity -> 1000

Transportation expense -> 100 $

Transportation Vendor -> V1

First shipment received on 01.10.2014 for 250 qty

Shipment 1 details:

Quantity received -> 250

Transportation expense -> 100 $

Transportation vendor -> V1

Shipment 2 Details:

Quantity Received -> 300

Transportation Expense -> 150$

Transportation Vendor -> V2

Shipment 3 Details:

Quantity Received -> 450

Transportation Expense -> 250$

Transportation Vendor -> V3

Vendor cost + Expense value should be loaded to inventory after GRN.

What process to be followed

Thanks & Regards

Ranjit