Clubs charge extra for playoffs because CAHA, SCAHA, and Norcal also have to charge the clubs for the ice, refs.
If your team makes playoffs, your practices run longer, so you pay the club for that extra ice and possibly, for the coaching.
The alternative: roll up that cost into each club's/team's dues.
Yeah.... as if the clubs and teams would want to pay for ice, coaching, refs they don't directly use? I don't think so.