English for Today by Ganiu Abisoye Bamgbose (Dr GAB)
Grammar in Marketing
~Black marketers~ take advantage of scarcity (nonstandard).
Black marketeers take advantage of scarcity (standard). People who sell on the black market are black marketeers.
Make sure you buy from my ~customer~ (nonstandard).
Make sure you buy from my preferred tradesman (standard). A customer is a person who buys goods or services from a shop or business; therefore, a buyer can’t have a customer. A person engaged in trading or a trade, typically on a relatively small scale is a tradesman.
GAB

I always follow your online classes. So nice
Black marketeers take advantage of scarcity (standard). People who sell on the black market are black marketeers. Please, in regards to the above sentence, why is ee there ?