As a matter of priority for you, your league is more important and your trainees are also more important than the revenue from the cup. Especially with the gimped "welcome to the current US economy" rewards. Always try for optimal training minutes for all of your players you are working on, you know that.
I believe there is a cash prize for the cup this year, possibly not. If you do win, you get to go head to head with the top teams from the world. Ask yourself, do I even want that? I dont just yet and I dont believe you do either.
Focus on promotion mate, the rewards are more important. And its basically a scrimmage with rewards, so the economy is just extra, if you can't make it without the cash you were messing up to begin with which I dont think you are.
Accept that some days you are the pigeon and some days you are the statue. Dilbert