Nicotine sulfate is a pesticide formulation used in agriculture to control pests in crops. While it may be available for sale from certain suppliers, it's important to note that its use is highly regulated due to its toxicity and potential risks to human health and the environment. If you're interested in purchasing nicotine sulfate, I recommend contacting agricultural supply stores, pesticide distributors, or online retailers specializing in agricultural products. Be sure to follow all safety guidelines and regulations related to the purchase and use of nicotine sulfate.