Goods purchased like this are called wholesale goods and the act of puchasing these goods is known as buying wholesale.
From Wikipedia:
Wholesaling, jobbing, or distributing is the sale of goods or merchandise to retailers; to industrial, commercial, institutional, or other professional business users; or to other wholesalers and related subordinated services.[1] In general, it is the sale of goods to anyone other than a standard consumer.
According to the United Nations Statistics Division, "wholesale" is the resale (sale without transformation) of new and used goods to retailers, to industrial, commercial, institutional or professional users, or to other wholesalers, or involves acting as an agent or broker in buying merchandise for, or selling merchandise to, such persons or companies. Wholesalers frequently physically assemble, sort and grade goods in large lots, break bulk, repack and redistribute in smaller lots.[2] While wholesalers of most products usually operate from independent premises, wholesale marketing for foodstuffs can take place at specific wholesale markets where all traders are congregated.
Note though that this refers to the purchase of finished goods for retail sale to the public. It doesn't necessarily cover the purchase of raw materials for the production of retail goods. However a chef may, for example, purchase a large bag of flower wholesale because that bag of flower was sold by a wholesaler not open to the general public. Wholesale purchases are often not subject to sales tax the way retail purchases are.