I'm a masters guy. I just did a 7 year stint on the camel masters, and now I'm going back to the blue (to match my new cloth). The camel feels drier than the blue. Both were bought at the same time, stored exactly the same, etc... and that light green is different, too.
I'm never going to be paying much for chalk. I could never see going over $1/cube.
I'm not sure chalk makes much difference in the physics involved. Did Dr. Dave ever address this or do any testing?
But for an ideal chalk, I want the following features:
1. Color matches my cloth, whatever that may be (so make a variety of colors)
2. Sticks to tip well, but not the balls. I'd love it if it didn't stick on the balls at all
3. Doesn't make a mess everywhere (balls, cloth, hands, cue, etc)
4. Doesn't roll around
5. Doesn't require any special care (leaving in a moldy basement or oven drying)
6. Cheap, no more than $1/cube
Now, as for the tip between the samsara and phenolic, one already exists. My older Lucasi jump cue (JC2000 model?) has some layered tip that seems as hard as phenolic. I would take the samsara jump/break tip over the super hard leather any day of the week. Getting chalk to stick to that lucasi tip is a nightmare. The samsara on the other hand I can play with.
You may want to call Lucasi and get some of those tips for testing while you're developing your new tip.