i just do play the cards every once in a while, esp. when that Granger girl has zero mood, since i don't use the cheats, except money, with gifts limited to one each per day, one has to have something to take the edge off. right? it takes what 2 full days until she's calmed, or more. also when she loses she'll do stuff even while mad at MC.
don't remember when i last actually bought a pack; the specials you get from early wins usually been enough to win any of the stage one challenges. going by what them Weasel boys said, this might not work for future stages.. at least the potential to keep losing is hinted at "so they have to buy more packs to win! we'll be filthy rich!" along that line.
anyhoo, it being a minigame, i don't think the devs will spend too much time on fleshing it out. not too many players will make full use of it, as long as there aren't more storyline connections. efforts. it may take quite some time and work just to balance it out and put the "Options" bit into the code.