Generally the cheapest fro Amazom is by Cinnado. I have a video on installing it my channel as well. I've bought this model for as low as $9.50 shipped. https://www.youtube.com/watch?v=phqR49t75Ak
It looks like right now it's available for 14.99 less the 25% promo code, that's $11.25 USD shipped, for OSS hardware? Niiice!
PTZ works great although none of these devices actually HAVE a zoom apability.