I can understand being reluctant to throw stuff out, but they could try making it lots cheaper (50p is better than 0p, and 50p+new stock is much better than 0p+turning new stock away - and a lot of their prices aren't actually that cheap to start with, compared to what charity shop stuff cost in my day).

I know they only have volunteers, but also if someone could do an hour sticking a little flyer through letterboxes round those bits of Bermondsey which have lots of young families saying "we have kids toys going cheap this week" or whatever. This is I'm sure the sort of thing lots of people like me who don't have the time or inclination to sit running a shop would happily do.