Is it permissible for the wife to purchase household necessities without her husband's consent, and is the division of expenses between the two wives fair, knowing that one receives 700 Riyals and the other 300 Riyals, and that the first wife's home is complete while the second wife's home lacks many things?

The wife's maintenance should be according to what is customary, and to the extent that suffices her and suits her standing. Justice dictates that each wife be given what suffices her and her children. If one of the wives has children, she is entitled to more maintenance for her children, and equality should be observed between the wives in the maintenance allocated to them personally. As for the furnishings of the marital home, you have the right to obtain what is indispensable for you according to custom. If your husband does not provide it, you are permitted to take from his money without his knowledge to purchase what you need. If you wish to purchase from your own money or from the surplus of your maintenance, he has no right to prevent you, because the maintenance becomes your property.