In Japan, sushi is definitely one of the more expensive foods. You can't really use yesterday's fish as authentic sushi uses fresh fish which you can't eat the next day for obvious reasons.

I make sushi weekly.

I've had thanksgiving sushi - turkey, rice, cranberries and breenbeans

Pizza sushi - rice pepperoni, pizza sauce and cream cheese

Normal fish sushis

Burger sushi, old burg meat, tomato, lettuce and cucumbers

Also made special sushi for my dog that had rice and various scraps of meat/chicken feet etc...

It's literally endless. It's 100% my new sandwich sin e I've stopped buying all breads