Customer specific price list in repair order

Hi,

We had customer specific repair price list defined in system.

By default system shows default repair price list which is common to all customers.

But there are few customers which had negotiated repair price list.

Business needs to default this negotiated repair price list to that customers i.e on ship line, So that user would not allowd to manually select everytime..

How to do that.. Need guidance.

Amol