The one I was initially interested in is the 200DFC6-R but I found a batch of 200DFC6-P's for sale at > 50% off new prices on Ebay. New these run about $165. The ones I found on Ebay are listed as "New Unused" and cost $75+$6 shipping. Still a bit pricey if you ask me. But I think worth a try since between 10-100 MHz Insertion loss is between 50-90db! 90db at 100 MHz.
The "P" model is 1000nF, the "R" that I wanted is 4700nF the "R" model is 70-90db between 10-100 MHz.
It's good to know these are available at least.
I've ordered the 200DFC6-P from Ebay.
These things are small tho so may be interesting figuring out where to place things around it. Nearly 6" long and 1.5-2" wide.
Top row is in inches, bottom in mm.
Here's part of the datasheet on them. Click the image for a large copy or go here to download the whole thing.