Acheter par francs et vendre par écus = To buy in the cheapest market and sell in the dearest; To sell at a high profit.
A stranger addresses a friend of the author: Pourquoi ne parle-t-il point de vendre et d'acheter?
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "vendre" in a variety of sentences. We hope that you will now be able to make sentences using this word.