Unless you have a legitimate chance of playing 50+ hours and having a good w/l ratio, you shouldn't even bother tbh.
The rewards for older players are mostly useless since none of these cards are used in meta decks or can be farmed other ways, and only the first prize is truly impactful.
To each their won reasons to play, the competitive environment of the kc Cup is one of my favorite aspects of the game and who knows, perhaps one day I will reach the top