If you're asking whether the 300s + the ck91/92/93 caps is a good, inexpensive mic system, I'd say yes. Some here argue that they lack some detail relative to other mics, and that's probably true, but I'd also say, relative to what? Compared to Beyer MC930s, the Beyers are better. Compared to the Busman mics (which are $500 new) it seems to me that the Busmans have more brightness and top-end, but lack the rich bass of the ck9x series. I made some good recordings with these mics when I had them that I still enjoy listening to. They have the advantage of multiple patterns, and even the ability to run a remote active cable. And frankly, even if they aren't their signature product, they're made by AKG, a manufacturer with excellent quality control and reputation.
I think there is a set in the YS for less than $400. That's an extremely fair price and IMHO there is nothing better for that price that I know of.