At this point, I have tasted most of the menu. For the price range, it is so hard to go wrong with Manpuku! Always modest and welcoming, this is a go-to for social eats, where folks new to Japanese cuisine can get acquainted with tasty food. There are also dishes like natto for those who have acquired the palate. On average, you could easily satisfy yourself with around $10, but I tend to get wide-eyed and spend up to $15 for myself.
Off the top of my head, my favourite menu items include the imo mochi, hotate rice (scallop and egg), and takowasa (wasabi pickled octopus - as long as I'm not finishing it myself). Their entrees are all pretty safe. Just note that this is not a ramen restaurant, and that their ramen (which is just 7.99) doesn't come in a rich broth or with premium toppings.
P.S. They do tend to run out of goodies towards the end of the day. :)