Maybe a dumb question, but have you tried Wal-mart? I tried all over near me, home despot, nurseries, etc. Couldn't find what I wanted. Then I was at walmart the other day and there they were. They have stuff in 1.5 cu. ft bags for $3 ish. Says soil conditioner, also says aged pine bark fines on the bag. Just the right size, very little dust, very little wood. I live in Maryland, so maybe it's different by you, but it's worth checking it out if you haven't already.
And yes, the product could be different in different areas. Or even from year to year. I bought a product called "claybreaker" at home despot last year, and it was pine bark fines. This year, I went back to get it, bought a few bags, got it home, and it was mostly leaves and twigs, partially composted. A vastly different product. Probably works the same as a soil amendment, but much different if you're using it as the primary media in pots.