This is a good question.
I dug around in the Contact Lens forum on this site and found a couple people who had similar problems finding anything in positive power - you could search around in there a bit more, I didn't dig really deep.
I think the usual manufacturers of costume lenses are only for near-sighted/myopia/negative powers or non-prescription; and the rest has to be custom-made, which is why they are so expensive.
This was also really difficult to google! But I did happen to find one contact lens website (www.visiondirect.com
) that carries the "Custom SFX" range of contacts that do come in positive powers. They aren't quite under $100 but some come really close.
Some of their red contacts that appear to come in positive prescriptions: Paine, Kabuki, Blackgate Orc, and Harpie. Harpie is a bit more, at $125. The others are about $105.
So far as custom lenses go, I've heard good things about www.9mmsfx.com
, but you've probably already discovered, they are not inexpensive.