To what extent is it religiously permissible to add a specific amount to the price of merchandise requested from an employee for sale to other customers outside the company, with the added amount being returned to the employee as his profit?

It is not permissible for employees to perform private work during official working hours, because their services during this time belong to the employer. Similarly, it is not permissible for an employee whose job is to sell computers to take any additional amount on the official sales invoice for himself, or to pay a portion of it to another official, as this additional amount belongs to the company, not to the commissioned employee. Whoever has done this must repent to Allah, return the amounts taken in this manner to their company, and advise others.