world traveler question

Each day I do a little research on Patagonia and write an e-mail or two to
start developing contacts there.

One thing that has popped up is the high cost of renting a vehicle.

It occured to me that maybe I could buy a used one ( probably 4x4 ), use it
60 days, and re-sell it before flying home .. for less than renting for
that period. Before I give this more thought and research, let me ask ....
is there some hidden ( to me ) reason why this is an absurd idea unworthy of
pursuing?