If you win 20% of god fights, and you win a card 10% of games you play (roughly), then you win a card -- valued at approximately 1,100 ep -- every 50 games you play against a False God. You also win, in those 50 games, roughly 300 ep in money (assuming you average 50 HP when you win a game). That's 1,400 ep won.
For those 40 lost games, you pay 1200 ep (30 ep per loss), making False Gods a slow money-making proposition at 200 ep per 50 games played. You're literally better off playing vs. lvl 1 AI at that point. 50 games will take a hell of a lot less time, and you'll make 250 ep minimum in the same number of games.
On the other hand, if you win 80% of your halfblood fights, and you win a card 10% of games you play, and 15% of those cards are upgraded, then you win four cards -- valued at (.85*50+.15*1,100), an average of 207.5 ep -- 830 ep worth of cards -- every 50 games you play, and you win roughly 20 ep per win for 40 wins -- 800 ep -- in those same 50 games. Thats 1,630 ep in 50 games. Much better.
Of course, Masteries and other events will affect these numbers, but that's a good idea on how to calculate what's the most profitable route for you.
