Yeah.. I think that's more like it. I bought a few caps (77mm, 72mm, rear cap, body cap) a couple of months back from CP and I still have a 72mm in the wrapper. Price tag is around $12.5. Just bought a 52mm cap a few weeks ago from Max Photo at AMK Hub was only $5.50.
So as hacknet mentioned, get it from CP, NSC, Max Photo or Lords. MS Color doesn't seem to carry. TCW carries 'fake' ones (at least for rear cap) and sells them at almost the same price Cathay sells the real ones at.