I recently came across the following article on Yahoo on crocs which can be dangerous for young children. They are comfortable, but I wouldn't have my 2 to 5 year olds wear them till their foot size won't be...
Guidelines for the Successful Auction Selling of Second Hand Used Baby Clothing Items. Ensure all items are in great condition - of saleable value. Dont sell trashy, dishevelled, ripped, pilled or stained...