Believe it or not, I found the CD at a "used record" store for $5.99 just recently. I was amazed at my luck. It is great to listen to the bands that were extending the canon in the "middle period" - after Monroe and pre-Dirt Band. Bands like the Dillards and the Osbourne Brothers - and Red Allen - broaden the scope of the music.
I had a chance to open a show for the Osbournes in Chicago back in the early 70's, which was an eye-opener. Me and the boys had been listening to a lot of Flatt & Scruggs and Bill Monroe and thought we knew (as well as young chumps from Chicago could) what Bluegrass was supposed to sound like. We knew when we heard something different in the Osbournes, but we couldn't really put our finger on it. They were bringing the sound a lot closer to what Country Music (the best of it anyway) would become in a few years. I get the same feeling when I listen to Red Allen. There is something in his singing, at least in my mind, that sets him apart from the Jimmy Martin/Lester Flatt school and reminds me why I began to like Country Music in the first place.
Anyway, it's great stuff and well worth finding even if you have to pay full price.