I know that there's been rumblings of 7/11 in the USA spinning up more food options with an eye to how things are done by its parent in Japan, but it really can't come soon enough. Get a move on! 7/11 in Japan with its onigiri is amazing and I'm desperate for these style of convenience stores with their options to make their way over here to USA and Canada.
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.
I think in many metros they could have a market esp if they did some sort of anime tie in.