Great question! and thanks for the feedback, I really appreciate it.
I"m not sure, I have toyed around with both ideas. I do think I'll make them a purchas thing, but only after you have unlocked them? Not too sure yet though.
Another thing though, is I want to make the player have to purchase things WITH their workers. So something may cost 10 or 20 taps for example. It's most likely how I will make future bartenders get unlocked.
Haven't got ther eyet though, what do you think?