Would you pay $6.99 for a onigiri?
Sure they're ~120 JPY-240JPY. But it wouldn't be the same price. Plus would they really sell them in the USA?
Same for more of the other options, I don't see it really happening. There's a reason hotdogs, nachos and whatever else they offer in USA is the norm. That's what the market takes and settles on and even then, it's over $5.