I bought most of my Bento stuff from a store called Ichibon Kan which used to offer it's products for ordering online. Ichibon Kan is like a Bento Dollar Store. Not the best quality but SUCH cheap prices! I was so bummed when they stopped the online service. :(
BUT I just heard of a new cheap bento store online! It is called fit All the bento stuff seems to be about $2 each! Check out the boxes and accessories.
I know absolutely nothing about his company but I'm hopeful and excited!