"Is it worth it to check out garage sales and the like? Are there other online sources I should be keeping tabs on? Any help is much appreciated. "
You would need some weird-ass garages to find what you want.
1977, Blue Boye (Mbari, Screwgun)
2002*, The Collected Poem for Blind Lemon Jefferson (w/K. Curtis Lyle, Ikef) - Mbari, issued just before Dogon A.D. in '71 or '72. IIRC. It was sold out when I bought Dogon A.D. from Julius.
Haven't had a chance to listen yet but the concept and the players are promising.
Joe McPhee: tenor saxophone
Jason Adasiewicz: vibraphone
Josh Berman: cornet
Jeb Bishop: trombone
Tim Daisy: drums
Kent Kessler: bass
Fred Lonberg-Holm: cello and electronics
Dave Rempis: saxophones
Ken Vandermark: clarinets and tenor saxophone