You are considering buying either this vintage derailleur Bianchi road bike, or a single-speed/fixed-gear Bianchi brakeless track bike?

That's like saying should I buy this sports sedan, or this motorcycle. Totally different things.

I think you should figure out what you want and need, which will depend on what sort of riding you plan to do, where, what distances, how hilly, how much traffic, carrying anything?, rain or shine? And you should make sure you know what size frame you need. Do not buy any bike until you answer those questions.

If those bikes were half the price, they would still be too expensive if they turn out to be the wrong bike for you. Especially when you're on the second bike in traffic and notice that you have no brakes.