I have pins in the basement, living room, dining room, family room, entry hall, and still have some in the garage and in storage (don't have time to do or finish any restores that I have started at this point). I have had 1 (1st pin) for 15 years...I am pretty content with what I have (I know, I know!!) and I very seldom sell or trade any of them and don't have any at this point that I would be ready to. So I just enjoy what I have! So I wouldn't say "never", but I very rarely sell/trade a pin!
Phoebe