Hey dog sh$t or whatever your name is. For what its worth, the vast majority (other than a few very cheesy made for TV set ups) of golf tournaments are prize money only. If Tiger Woods goes to the US Open and doesn't make the cut, he doesn't make jack, got it?
Deeper prize money in marathons equals deeper and better fields. If you enter and are having a bad day, drop out and use the early miles as a workout, and have a back up plan. The reality is that VERY few marathoners can demand an appearance fee, as evidenced by the existence of this thread.