Vintage Toys (Can Plastic be Vintage?).
Playmobil
Playmobil sets are plastic with LOTS of pieces. They aren't sutiable for little kids, but are great for older ones with some imagination. The bane of selling these on Ebay is the missing parts problem. If the set has been played with it most likely is missing something. Many times pieces from more than one set get mixed together.
If you want to be sure you are selling a complete set you need someone with the time and interest willing to put the whole thing together so you can take pictures proving the completeness.
I know you can buy bags full of random Playmobil parts. I have thought for a long time a kid who likes to put these sets together could make some spending money by buying parts cheap, figuring out which ones they are, and selling them individually to people who are trying to fill in a set. It's one of the ideas I talk about on our Make & Sell website.
Vintage Doll Houses & Furnitureg
These old doll houses are a giant pain to ship without damage, but are very popular. They are easily broken but we notice they attract young girls from across a crowded room.