I am looking for a good fairly cheap outdoor scanner antenna and where they can be found.
"good" and "cheap" are a bit of a contradiction in terms!

Under the heading of "Cheap", there's always the bulkhead antenna connector mounted to an electrical junction box with a coat-hanger for an antenna soldered to the center of the connector, radials mounted off the corners of the junction box, and a "U" bolt (for clamping to a mast) on the side. It works, but don't expect anything spectacular.
As far as "good" goes, I'm reminded of the following proverb (saw it in a bar once, several decades ago): "If you want good, clean oats you will have to pay a fair price. On the other hand if you're satisfied with oats that have already been through the horse, they're a little cheaper."