Thanks again,  but I re-iterate on the primer from #10 adding the pointers from

I'm hoping for an answer like this:
a) The dev(s) launched coin on Day 0 and came up with price P1 that was hardcoded
b) Miners/ innovation/ difficulty level etc factors cause an increase/ decrease of
c) Thus, at time T1 of launch the price was calculated by to be
d) At time T2 price increased/ decreased by or became

Or including the merchant (like @DOGE12321 said)
e) Merchant M1 derived price PM1 , M2 derived price PM2
f) Exchange E1 averaged prices PM1, PM2.. and came up with it's price PE1, exchange E2 likewise came with PE2
g) preev averaged the prices PE1, PE2...

Not a very elegant primer, but hopefully you get an idea. It's the derivation of the price step by step than the theoretical knowledge that I hope to find here.