I don't think it's sad keeping old teddy bears , it's your childhood and has memories surely? . If it gets to the point where your house & rooms are so full of cuddly toys,it resembles an amusement arcade or nursery....then maybe you might have to part with a few .
But that's more to do with if it becomes a inconvenience to keep them all ....ie taking up too much space or something, guess it depends on how much room you have

.