Interest by Dino 308, what is the daily investment?

Hello,

I am interested in buying a Ferrari Dino 308 GT4 in 1979.

Prices are "relevant" between 15000 and 30000 Euro.

Now here is my problem, everyone around me discouraged me from buying one: "It's a money pit, you do not even realize! .

Personally I'd like to know the average price of maintaining a 308 Dino (with a change of brake or other usable parts here and there).

Now put the essence, what represents, for me, maintains about 308 in (for a very correct state).

My goal is that this purchase an investment home for later, is this a car that has a future in its listing?

Thank you for your reply.