The price on pythons is varying by huge amounts right now, apparrently partially related to misperceptions by people selling them about whether or not Colt still makes them, or ever will make them, or is even still in business.
I have seem very similar pythons selling for anywhere from $500 to 1000+.
The sellers are either very confused or trying to gouge buyers right now, in GA and FL right now anyway.
Personally, for a standard, nothing special blue python with 6 inch barrell, $600 or maybe $650 is as much as I would spend.
Colt does plan on re-introducing the python, and when they do, I expect prices will fall some on the used models.