Very sound advise.Dangerous question, I think. I might be way off base here, but it seems like you want to buy a 412 as daily transport on a reasonable budget.
All I can say is: if you have not won the lottery, then please do yourself a favour and steer clear. The car can handle 200k fine, but your wallet won't like it. Everything about a 412 is expensive. I've just heard a couple of prices: new windscreen? $2,000. Typical original dashboard switch: $600. The list goes on and on. They are very, very expensive cars to run, even for Ferrari's, mostly because so few were built.
You'd be much better of buying a recent 456 and running that on a daily basis. That car was at least built to do large mileages, and there are a lot more of them around making spares more manageable.