How to Do Item Restrictions

Hi All,

Occasionally our company will have a deal with major customers and sell few items at special price for that customer under a new product brand.

For that we will have New Set of items created.

All the other products can be bought by anyone but these Branded Product can be bought only by this customer.

I have explored and tested to have a Customer group  set for all the other customers , then have preference setup  to  direct it to a invalid status flow if any other customer tries to buy it.

Example set sold-to  Customer category Blank for this customer