Is your 'accumilation' causing problems in your life? No? Then you are a collector. As far as how much of a thing is too much? No such thing. That is a number only we can set for ourselves.
I have sold down my model kit collection to leave only GM trucks... almost. Man do I have me some die cast truck banks, though. I probably was caught up in some sort of obsessive behavior with collecting there for a while. It was a high for sure when I'd buy another car, truck, cycle, bicycle, outboard motor, truck part, pressed steel toy trucks, die cast old & new, and on and on. My wife had things she collected and I bought more of her collection than she did. I just had to buy something!!!!!
I'm glad I have gained control of those impulses. Not 100% happy and I still get every impulse. I still want stuff!! But maintaining a manageable life is what's most important to me now. Still working on getting there, too
There will be other vehicles in my future, and I'll be keeping them