William Henry had some, I think I remember seeing some from Klotzli in one of AG Russells catalogs. I know that William Henry did, played around with one at Country Knives in Lancaster. As for traditional friction folders, I have seen a few customs, just in the Baltimore area. The one I remember was made by Frank McGowan, very nice piece. I've seen articles from time to time on making traditional friction folders in Backwoodsman, and came across an article in Blade, from several years ago, about a Roman friction folder. Many on here would know much more than I.
As far as around 50 bucks, the Backwoodsman articles on making your own would be your best bet.