@Cann
Again, I agree and was being lazy. I use both Dolo and Calcitic, depending and should have explained my reasoning better.
Dolomite, local, ~$4+/40lb bag
Calcitic, local, ~$15/40lb bag
oyster shell flour, wherelocal, ~$15+-/40lb bag, but shipping to my AO brings that up to $45+ for that...