ms911,
I don't think you can purchase just the cups.
I changed the complete wind sensor about 2 years ago. I can't remember who I purchased it from (I think it was directly from Girard), but it cost about $75. When it arrived a few days later I changed it out and installed the new one - it works great. I had hit a tree limb while driving through a subdivision in New Orleans and broke the old one into several pieces.
Girard is a nice company to do business with. They make a great awning!
Tuga & Karen Gaidry
2012 Honda Pilot