Prices are relative to condition and demand.
I own 3 pairs of Nak CM300's.
some are a bit nicer than others.
On average, they seem to be going for 100-125 dollars a mic, right now, with the cp1+cp2 capsules. It's hard to beat the bang you get for the buck. Again, the price is relative to the condition and demand. I just happily paid 625 dollars for a pair of CM300's that are MINT, with cp1's, cp2's, and CP4's, and a Nak MX100 mixer, and two custom 9 volt battery boxes. The price may sound high, but the mics literally look brand new, no blemishes, orginal owner, boxes, manuals, all accessories, etc.. And the CP4's windscreens are perfect. I'd almost swear the owner had kept them in a time capsule, they're so nice.
The Cp1's are the cards, the cp2's are the omni.
The cp3 is a "super omni directional pinpoint capsule" per the original Nak Manual. I have yet to see one, nor have I heard of tapes from them.
As for what the mics are worth w/o capsules, I personally wouldn't buy them w/o a capsule, as these are 20 years old, and it's not that easy finding replacement parts. If you lose a capsule, or god forbid, an attenuator, you're S.O.L.
As for the price of CP4's, well, they're much more rare than the regular cm300's. You could easily pay 150 dollars a piece for them, if they're in good shape, and have windscreens. They seem to sell on FleaBay for 125 even in mediocre condition and w/o screens. (and quickly too)
Peace,
Spinman