The Joe Henderson Blue Notes are all readily available, yet they were collected in a Mosaic box.
Mosaic's website states: "But when you consider how much was happening from 1963 to 1966, the years covered by this collection, and contemplate how many different looks he provided through that time period, you can’t ignore his significance as a saxophonist and as someone central to the music’s development." In other words, the box prompts a reassessment.
And going back to "readily available," Amazon has the following only available through third-party vendors: Chillin, Keep The Spirits Singing, Davey Blue, The Gift, Song For The New Man, I Remember Brother Ray, and Life.
Finally, should Mosaic take my suggestion and issue a Fathead box, you don't have to buy it. Others will.