A botnet is a network of infected computers that are controlled by a single entity, known as a botmaster. Botnets can be used for a variety of malicious purposes, such as sending spam, launching denial-of-service attacks, or stealing sensitive information. To buy a botnet, you will need to find a seller who is willing to sell you access to their botnet. There are a number of ways to find botnet sellers, such as through online forums or dark web marketplaces.
Once you have found a seller, you will need to negotiate a price and payment method. Prices for botnets vary depending on the size and quality of the botnet. Once you have paid for the botnet, the seller will provide you with instructions on how to access and use the botnet.