Buying a plane versus renting

Just wondering if anyone has some experience on the above subject. I'm
looking at building up some time (500 hours or more) within the next couple
of years. My two options are to buy an older 172/Arrow etc or just to keep
renting which is very expensive.

If I can find a decent airplane, in the end, I assume purchasing one to use
for a couple years will be cheaper. Am I wrong about this? Any pitfalls I
should be aware of?

A second question is regarding purchasing a newer 172. I know the initial
cost is more, but given the age is it probable to save money via maintenance
compared to an older airplane? What about resale on a newer 172 (year 2001)
versus resale on an older 172/Arrow?

Any input is really appreciated.

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Thank You,
Ryan