Replacement Toy Pieces
I think clever children with experience putting together toys that require a lot of assembly, such as Legos™, could make some spending money buying collections of toy parts and pieces on Ebay and then identifying and organizing them. If you look through the list below you will see boxes of toy pieces of various kind for sale for very little money. If your kids have been playing with the same kind of toys, you are no doubt familiar with the frustration of having one oor two missing pieces.
It seems to me that kids could have a lot of fun going through boxes of these parts, identifying which toy set they came from and reselling them. Even grown-up "Kids" find this interesting! The links on the left go to various toys with which we have enjoyed doing this.
How would they re-sell them? I think the highest prices would come from the sale of individual items from your own website. With the proliferation of easy sitebuilding tools this is not beyond the technical skill of many early teens, or even younger kids. I would advertise the sales site by always haing one or two toy pieces for sale on Ebay and create a ME page that points to the other website. You can find other money making ideas at our make and sell website.
I think this could be turned into a very educational experience for home schooled children too.
We have decided to take our own advice and begin publishing our collection of toy pieces.