Is taking the price difference between what the company owner demands ($1000 per minute) and the lower price I found permissible or forbidden, knowing that informing him of the lower price will forfeit my right to this difference?

O questioner, you are an agent for the company, not a broker. An agent is not permitted to take the surplus for himself; rather, it is the right of his principal. The fact that the company owner, if he knew, would not give you the price difference, confirms the unlawfulness of your action. Therefore, you must pay the price difference to the company owner.

You must also say: "By the grace of Allah, and then my personal connections," because the Prophet, peace and blessings be upon him, said: "Do not say: 'What Allah wills and so-and-so wills,' but say: 'What Allah wills, then so-and-so wills.'" This is because the conjunction "wa" (and) implies combination and partnership, while "thumma" (then) implies a delayed sequence.