There are ups and downs to it. A lot of your time is going to be cross country solo so owning your own plane during this time can have its up sides. 250 hours x $149 rental rate wet is 37k. 250 hours of fuel in a C172, depending on your area, is around $10.5kish. If you buy a plane with plenty of time left on the TBO you can sell it after and won't take much of a loss if any. Do all of your flying quickly and might be able to skip too many trip to an A&P.
If talking frustration, just rent and eat the 20k difference. You will be paying for the instructors either way.