Piston rings for a Kawasaki KD175 Dirtbike

Hi, I have a 1976 Kawasaki KD175 and I need new piston rings. I went to buy some off of ebay but they want about $50 for them. For a bike I don't want to dump a ton of money into I was wondering if there is a good alternitive that will work well but are cheap. Anybody know?
I hope someone can jump in and help you.
I ended up spending a bit over that for some Honda CR60 rings, 3rd oversize and had to have them shipped to a friend in England so he could ship them to me because I could not find them anywhere else and the ebay seller would not ship to the states!
Those NOS parts get pricy!