Is money acquired from a deal secretly revived after the company canceled it considered haram money?

As long as the inquirer has communicated directly with the manufacturer and explained what he wants, the issue of working for his own account within his company's field of work has been removed.

The inquirer is not a partner of the client or the manufacturer; rather, he is a guarantor or surety for the product's price with the client. The contract of guarantee or suretyship should not be a means for earning and profiting, because suretyship is a gratuitous contract for which compensation is not permissible.

The legitimate solution is for the inquirer to agree with the manufacturer on the product for his own account. Once he possesses and acquires it, he can then sell it to the client.