You can typically purchase nicotine sulfate from suppliers that specialize in agricultural chemicals or pesticides. Online platforms, agricultural supply stores, or specialized chemical suppliers may offer nicotine sulfate for sale. However, please note that the availability of nicotine sulfate may be restricted or regulated in some regions due to its toxicity and potential environmental impact. Ensure to verify the legality and regulations regarding the purchase and use of nicotine sulfate in your area before making any purchases. Additionally, always follow safety guidelines and use protective measures when handling and applying nicotine sulfate.