Do not consider any employee discount as wages with respect to qualified property or services if the discount does not exceed the following.

1. a. 

   In the case of property (other than real property and other than personal property of the kind held for investment), the gross profit percentage of the price at which the employer is offering property for sale to customers.

2. b. 

   In the case of services, 20 percent of the price at which the employer is offering services to customers.

Under a special rule, this exclusion applies to discounts provided by a department store to employees of another employer (such as a cosmetic firm) who make over-the-counter sales of merchandise within the store, giving the appearance to the public that they are employees of the department store.