Help with purchase of 964 convertible

Hello I’m newly registered and I’d like to buy a 964 and, as a layman, I’d like to ask you a few questions (never had a Porsche before) I say in advance that I live in Switzerland, I’m looking for a used car, I’m looking for a 40.000-45,000 euro maximum and it won’t be a second car, but I don’t use the car every day, rather on the weekends. Unfortunately, no one who knows about cars in particular will check the car professionally. My wish would be in principle a black convertible, with max. approx. 100k km. 1. How much cost per year for the maintenance (except of course insurance/control sign fees) do I have to expect? 2. Which vintages of the 964 should I avoid? 3. What must I pay attention to, except maintenance / checkbook? 4. Compulsory from a garage or also from private? 5. What are normal prices for a black convertible, with max. approx. 100k km.? 6. What does a Porsche cost? to have a new paint? (if I don’t find a black one..) Must honestly admit, be afraid to buy a scrap, and spend not a little money for it 🙂 Thanks for tips