The cost is high for the same reason the costs are healthcare are high.
The system (in this case colleges) are responding to an environment where someone else pays the bills (in this cash government in the form of loans and or grants) This distorts the marketplace and causes prices to soar.
If you want the cost of healthcare and college to go down, simply outlaw health insurance and loans and grants and the price of both will drop 80-90% overnight.
A+ for you!
Bingo ... College tuition (at least, published “sticker price”) has increased since the 1970s at about twice the consumer price index “inflation rate”. The problem is hardly unique to Catholic colleges; Protestant and secular private colleges, as well as State colleges have shown the same phenomenon. Christian parents may want to consider that with churches and ministries operating on or near campus, your local Enormous State University might not be a bad choice ... and certainly less expensive than a private college. If your kid is studying science or engineering the godless mess of the arts and humanities studies in the State college will have minimal influence on them.
Soaring home, education and health care costs all share the same root cause.