What confuses me is that they don't say what the costs are, really.
There is something that says "Training cost is 20/sp, 30/mp, 20/action (action cost is only for songs)". That's kind of vague. Like, 20 points divided by the player cahracter's stamina, or what?

I think I'll just make up a rule for how much techniques cost. I'll be right on that.