It is legal.

Buying agricultural products at low prices and selling them at high prices is a legal act. In today's market economy, it is completely in line with the laws of commercial operations. Merchants will do it if there is no profit. It is profitable. It is a business and a routine of the economy. However, the country will never allow unscrupulous merchants to accumulate and destroy the normal operation of the market economy. For individual illegal operations and unscrupulous merchants, the government has already had laws to restrict them.