Looking for a "cheap" MD/MC macro lens.

Hey guys,

I just bought a Rokkor-X 50mm f1.7 and I am very happy with it!

Now I find myself wanting to buy a macro lens. I am looking at the Minolta lenses on eBay and they're all $75+! This is just a small hobby of mine, so I don't want to spend too much money on lenses.

Is there a cheaper variation of a macro lens that will work on the MD/MC - NEX adapter?