1990 minivan (atrai) parts and reliability general question
 

I'm planning to buy a 1990 with defective engine and I wondered if these minivans had all the same weakness or symptoms and if it was easy to repair and get parts. I found a web site to get parts and their prices were pretty high. Is it always like that?
The seller of the one I have an eye on says that it is still starting and turning but with blue smoke and strange noise.
I would like your opinions please. :)

I forgot to mention that the one I'm planning to buy is an Atrai with 660 turbo engine