Is the increase over the price of perfume secured by the sales representative from outside the company's goods his right, or the company's right, or neither this nor that?

If some people appointed you as an agent to buy perfumes, and then you brought them from the company as their agent, and sold them to them at a price higher than the company's price, and took the difference, then this is not permissible. You must return the difference to its owners and repent, because you are an agent for them and for the company, and it is not permissible for you to lie or betray.

However, if people asked you for specific perfumes to sell to them, and you went and brought them from the company without buying them, then sold them to them at a price higher than the company's price, and after that bought them from the company and took the difference, then this is also not permissible. In this case, you must donate the profit, because it is not permissible to sell what you have not taken possession of or to profit from what you have not guaranteed.