On our last couple of Japan trips, we would walk into 7/11s for an inexpensive coffee, an egg or fruit sandwich, and also do some treasure-hunting for co-branded items with Muji/Uniqlo or others. It became a short and meaningful part of our routine. We loved the convenient locations and fantastic service at all their stores. Well done, Suzuki-san!
They are expensive by Japanese standards. Assuming you're American, you're benefitting massively from the exchange rate.
YT channel @japaneats is easily my favorite for seeing what's available in 7-11 japan.
On my trip there with a group of friends we would wake up and head to the local 7-11/Lawson/Family Mart. Even when we went into the countryside for the hot spring baths in Hokkaido there was a Lawson in town. 7-11 had the best food though. I loved those chicken teriyaki egg sandwiches, onigiri and the yakisoba-pan. But those chocolate swirl babkas were clutch. I once wandered in late night and cleared the shelf of them.