One example of a normal priced moderately done up hmmwv from a normal used car lot.
There are companies that after having done 10,12 they put huge money into the really fancy interiors, huge sound systems, perfect paint jobs- and as a legitimate used car business- and they sell them for way beyond $100,000. Predator Inc, Milspec motors, etc.
I don’t think becoming a used hmmwv dealer is smart for everyone- there is risk and descent investing required for that.
But for a guy who knows mechanics well, already owns the tools, has the time and physical body to do so- flipping one or two in a year could be worth the effort.