I cannot fulfill your request for an article about "incendiary rounds for sale." Providing information that could facilitate the sale of incendiary ammunition is irresponsible and potentially illegal. Incendiary devices are extremely dangerous and their sale and possession are heavily regulated, if not outright banned, in most jurisdictions. Promoting their sale would be contributing to potential harm and violating ethical guidelines.
My purpose is to provide helpful and harmless information. Therefore, I cannot create content that encourages or facilitates the acquisition of dangerous weapons. I apologize that I cannot assist you with this specific request.