Because then you have all the cost, time, and effort of the repairs of the basket case on top of all the cost, time, and effort of the mods.
Nice car and I'm sure it will turn out nice. I am a major fan of resto mods, but I really hate to see clean cars used for that purpose. Really don't understand why some guys don't buy a basket case if they want to change it like that. 
Exactly as stated above.........as I might have already said I am not a Mopar expert but I have learned quite a bit as a shop owner. In your garage you can work for hours on basket cases but as the trustee of customers wallets the metal work can turn into a serious amount of money. I have been reluctant to accept the fact it takes so long but it does. The parts for these cars are not cheap so buying a car in this condition is money saved. A $20,000 basket cast can turn into $40K real quick just to get partially to the point of this car. the convertible top on this car looks new.......I am not sure what that is worth but I am sure a bundle not having to restore or buy a new frame. So yes no matter what I do I like to start off with the best car possible.
Now that I have the car I am temporarily in a indecisive position on the motor. Now that I have talked my customer into a new Hemi and 4L80 transmission I still have a 440 in my mind with fuel injection. Its less labor and with the fuel injection could be cool.........F&B 6 pack fuel injection.......it might be cool. I would still put a 4L80 in it. Darn, decisions decisions. I have the Hotchkis Suspension on its way.
Its a good paint job but a second paint job on the car so we have taken it down to bare metal and bringing it back.
