Buy low and sell high is a well honored American ideal of capitalism. Nothing wrong with that at all.
What you cannot know is how Pantera owners form bonds of friendship that will last long after ownership of a Pantera. We are often described as a different breed of owners that come to value the friendships more than we value the ownership of the cars.
The owners that post to this forum and other DeTomaso sites are passionate owners, not passionate investors or car flippers. We regularly will bend over backwards to offer advice, wrenching assistance and parts supplying when fellow owners are in need. This site and others have a wealth of information that we encourage new enthusiasts to read, study and absorb. There are many pitfalls to be avoided in purchasing a Pantera and the online information, when properly absorbed, will provide the tools needed to make wise purchases.
There are far too many variables in evaluating a Pantera for any of us to concisely provide the direction you are seeking with just a single post to this thread
I wish you well in your endeavor, however, as others have pointed out, without truly understanding these cars you do run the risk of losing money if your purchase is not well vetted.