You rate it both before and after.
Because on one hand you have the matchups, the implications, the name power, and depth of card. Which for a PPV, is what you use to base your purchasing decision on.
Then you have the actual fights.
So any Bellator eventYou can express dislike over the matchups or the fights lined up while still appreciating the action itself. For instance, a card made up entirely of fighters the caliber of Cody McKenzie could turn out to be entertaining, but it still wouldn't be worth my money.