Is the 2000 Saudi Riyal visa fee rightfully owned by the vehicle owner, or should it be returned to the first worker who sold the visa, or to the new worker who bought it and works on a commission basis, bearing the expenses of his residency and labor office fees?

It is not permissible to sell visas because a visa is a sponsorship, and sponsorship is a gratuitous contract. It is permissible to take a مقابل (compensation) for it if the visa holder has incurred expenses or effort in obtaining it, provided that the مقابل is proportionate to his expenses and the fair wage for his effort. If the mentioned amount (2000) is equivalent to these expenses and wages, then there is no harm; otherwise, the difference must be returned to the worker.