My dad is thinking about buying a Colt Python. He said it looks like it's been shot but hardly. Very light line on the cylinder. My dad said it's from the late 70's. I think it has a 6" barrel and is the blued version. I think the price is 2200. I don't know anything about Pythons other than I know they sell for a lot. What are some things that I should ask my dad about it to make sure it's worth that amount of money? Is it even worth that money? Any advice would be much appreciated.

Though I personally think Pythons are wayyyyy overpriced....they are gorgeously made .  My roomie's is amazing.  Your dad needs to make sure the bore and the chambers are bright and clean and that the lockup from chamber to chamber is secure and even.  Also look at all of the side plate screws.  They should be unbuggered and clean.  For 2200 it should be nigh on perfect.
 

If the gun is complete, and a proper chamber rod confirms cylinder alignment, and crane is not bent, fold, or mutilated, then it's your wallet and your business.

But, know that there are no gunsmiths at Colt's who can work on this gun.  There are no spare part available from any source.  The fitting of the gun can be easily damaged.

There are gunsmiths at Colt who work on Pythons daily.  
Colt still offers full repairs and refinishing for the Python as well as most DA revolvers made after the early 1950's.