Well, If I did not sell mine, then I would not have the kinda cars I have now. I would have ...... the dozen beaters I started back up with a couple years back. I started back up collecting and bought about a dozen $5 cars, and now have over 130 worth over 10k.
I use to do it with my kids, now my youngest is 14 and could care less about a toy car. I talk redlines, he nods his head, and ignores me. Just dad talking cars.
So, I'm the only one that enjoys looking at my cars in my case. But like most of us, if someone offered you alot for a car, it we be gone, and searching for better one. Example: The staff car I have had for about a year. If someone buys it for what I want, then It will be gone, and I will find me another cool 442 to take its place.

I do have the cars I would never sell, the couple of RAOK I have received. And my Corvettes and 2 Rodger Dodgers that were my oldest sons favorites, since they remind me of him.

So I think alot of us that do not have disposable income for toy cars to look at, have what I call a Cool Rotating Collection.