I doubt that one parent having "sole decision making" necessarily means the other parent has to pay for "premier soccer" or private school. You should review your court orders to see what the current orders require you to do.
If your financial circumstances have changed or the current orders are not clear, you can ask the court to take another look. There may be other bases to file the petition.
"Premier soccer" or private school is generally not a necessity of life. Unless the parents can afford the activities and the children's lifestyle had included such activities before the divorce, the court likely would not require a financially strapped parent to pay for such activities.
You should review your specific facts with your attorney to see what legal options are available.