About a year ago, there was a guy here in Michigan who had about 20 National 9, 11 and 13 pulls in Candy and Cigarette of different vintages. He wanted 600 and change for the lot but would not sell individually. I needed a base for an older 9 pull cigarette and after several calls and visits was finally able to convince him to sell me a base. Unfortunately, I believe the rest went to the scrap man because he would not deal one machine at a time.
From what I have been told by an old timer in the vending biz (not sure if it is true), National kept the parts consistent through the years so many parts are interchangeable from model to model. Those machines are fairly plentiful in Michigan but I would not pay more than $100 for one. As someone already pointed out--HEAVY. Plus, if you put any amount of money into the restoration you will have more in the machine that you will ever get out of it. If buying for your use that is a different story but don't look to flip one of those for a huge profit. I guess in time those could become more desireable . . . . you never know.
Tim