What is the legal ruling on profiting from displaying a company's products at a higher price in my store, then purchasing them from the company after a customer orders them, given that the company does not object to this?

If you sell a commodity before possessing and acquiring it, this is impermissible due to the prohibition of selling what one does not own, and of selling before acquisition. This is based on the Prophet's (peace be upon him) saying: "Do not sell what you do not have," and his (peace be upon him) prohibition "that goods be sold where they are bought until the merchants transport them to their own places." However, if you do not finalize the sale with the buyer until after you have purchased and acquired the commodity, there is no issue with that. It is permissible to obtain a promise to purchase and a sum as a guarantee of the buyer's seriousness.