Ride and build-up what you like, want or have. Don't worry about what anyone else thinks you should have, unless you're motivation is to buy, build and sell in order to make a profit, in which case you do need to address the needs of the market.

I like to keep my vintage cycling as an inexpensive hobby, and limit myself to what I can pick-up very cheaply at yard sales, or rescue from the trash (over a dozen bikes last year). I save my cash for maintenance-type items, such as tires & tubes. If I had more disposal income I'd love to add Colnago's, Pinarello's and such to my collection, but I am content with my Atala, Fontan's, and Peugeot.