Indeed, the oxy-moron (pun also intended) was intendedI think it's a contradiction in terms to have "organised willy nilly" (though I can see that being the name of a band). I can't see why you'd purposefully say to yourself "right, I'm going to spend exactly 200 currency each day that I don't want the daily prize and I'll use what remains on the days I do want the daily prize". What's the purpose for that mindset? Is it to satisfy a chest opening craving without blowing everything?
Are you saying you need a reason for going willy-nilly? Wouldn´t having a reason already be making it non-willy-nilly? How about willy-nilly that by accident ends up being roughly 200 per day (an exact number will be close to impossible anyway). A willy-nilly that goes all-out in 1 day would also end up in that "all in 1 day" category by accident.