I would'n't be too hung up on mileage, more on condition. Some evidence of service history is always nice. And don't let DIY service history put you off, I would rate that far above Nissan Service history as an enthusiast takes alot more care of thier car and generally knows more about the car than most main dealers.
A well maintained one should go on for couple hundred K easy.
I appreciate its very hard to check, but if a seller mentions its ok to run on 95Ron, or it uses a little oil, personally I'd just walk away as its not worth the risk of any underlying problems that may have been caused.