I have plenty of Japanese coins, but where can one find modern Japanese banknotes at a decent price? A dealer sells them on MA-Shops, but they charge $11.00 postage, which costs pretty much the same as the 1000 Yen bill itself. And, correct me if I'm wrong, but I would think shipping a bill would actually cost less money (I've ordered coins from that site and paid far less postage for weightier items), but perhaps I'm missing something?
Where do you live? Anyplace that exchanges foreign cash for US cash. Coin/currency shows, local numismatic store.