After 35 or so years in the hobby my wants have changed many many times. I sell the stuff I no longer care about to feed my newest collecting wants.
With the bigger cards I do what I call card renting. Over time I have owned many of the big cards. I just don't have more than a few at a time. I sell one to own another.
I was gifted many vintage(1960s) cards as a little kid. I never got into collecting till my late teens. So I have always sold cards to make new purchases. After those 35 or so years in the hobby I have never spent a single penny out of pocket for any of my collection.
So if you see me selling something it is to buy something else.