Best price in conjunction with a pricing Formula

Hi experts!

A short introduction of my problem :

The company uses 2 price lists, one as a default price list and an other for special offers.

Some customer get's a discount of 50% (for example) on the default price list. Because of this some particular special offers are more expensive than the dafault prices of this customer.

Against this background im looking for a solution, that the customers always get's the best price, irrespective of the price list, they ar based on.

My idea for the issue:

1.      I've created a new pricing context "Special offer price". A function tranfers the special offer prices from the price list to this context (the value depends on the inventory_item_id of the order line).