I really hope that referees won't fuck that game up. It's Game 7, show some respect to players' efforts. I checked last 3 Game 7 finals and all scores were so low. Considering both teams' situation it's wise to play under 207.5 points for this game.
This is final and a deciding one, so I think going for under might end up in a loss.
I would bet for Over 209.5 if I were at your place as both the teams will be on fire having Curry and James as their attacking players.