One of my all time favorite sushi restaurants, Oeeshi offers plentiful portions for an excellent price. I've yet to find another sushi spot that will give you as much sushi for the same costs.
You're best bet at the restaurant is to go for one of the sushi roll combos: a large sushi roll, salad, and miso soup. Cost is usually around 5-10 depending on the type of sushi that you order.
A good quirk to know about the restaurant:
During the day and early evening they work almost like a fast food place, with you placing your order at the front and it being brought to your table. However, for dinner, seating changes into regular restaurant style, with you being seated and a waiter coming to take your order.