Supplier Rebates - Stock Based Purchasing

 Hi All

I have been tasked with finding a systems solution for the following.  I am sure that there is some standard functionality to assist with this process.

1) Purchase of 10 widgets at a certain price ($100 per widget)  Accrual for rebate is allocated at the same time ($4 per widget)

Accounting Entries

Inventory                               DR $1000

Inventory                                                        CR $ 40

Inventory Rebate Accrual    DR $ 40

2) These are then sold to various customers.  COGS charged at $96 per widget

Accounting Entries

COGS                               DR $960

Inventory                                                        CR $ 960

3) 3 months later the rebate is finalised at an amount of $ 4.50 per widget

Accounting Entries

Rebate Debtors              DR $ 45

Inventory Rebate Accrual                             CR $ 40

COGS                                                            CR $ 5

I have started to investigate advanced pricing but would appreciate if someone could point me in the correct direction.