Orbital Manga has a doujinshi (self-published) manga section. They say you set the price of your manga and if it sells you get all the money. Take in a copy of your manga for them to approve, once approved you bring 3-5 copies for them to sell on their shelves. Then you can tell everyone where to buy your manga in a shop :)
Sounds like a great opportunity for manga artists to get their artwork seen, great idea!