I have this pretty awesome Polish AK74 kit with an underfolder. I've yet to assemble it, so it's given me time to reflect a bit on exactly how I want to build the thing, and I don't think I want another underfolder.
So, I'm going to put the underfolder stock up for sale, having looked around online, I see that these stocks are going for about $130 + S&H. I'd be willing to part with mine for $120 shipped.
I'm also open to trades. Let's say one of those ACE-sidefolding para-style stocks and trunion or a set of plastic furniture and a rear trunion.
Make me an offer. If you have a fixed-stock kit and would like an underfolder, let's come up with a barter.