Hi, my first post on this forum, which I've been enjoying quietly for a few days.
I live in the South Loop quite close to where you're staying so can offer a few nearby selections. There's a new restaurant called Yolk in the building next door to your hotel (1130 S. Michigan) that has a good breakfast, brunch and limited lunch menu (you can check it out on the web), it's quite popular at the moment so there may be a crowd weekend mornings after 9. Prices in the $8-12 range. You are also quite close to the White Palace Grille (on Roosevelt Road, less than a mile due west of your hotel on Michigan), a 24 hour diner that is quite inexpensive (under $10) and serves good breakfast, lunch and dinner (I prefer their breakfasts to dinner food, the steak and egg breakfast is huge, and very popular). For breakfast, you're also not far (driving) from Lou Mitchell's, where you'll receive free orange slice, prunes, milk duds and donut holes with your breakfast. I don't care for their food that much (huge fluffy omelettes), and it is pricier than the other two, but it is a Chicago institution - that may appeal to you. Of these three White Palace would be my pick on a best price/value.
I would recommend a place called Joy Yee's Noodle shop for an unusual Pan-Asian food experience for out of towners. There are two nearby, the original in the Chinatown mall and a new, more spacious location near the UIC campus, both fairly close to where you're staying. They have a bubble tea bar serving an enormous variety of bubble tea smoothies (mango, papaya, coconut, peach, strawberry, watermelon, lychee, Thai coffee, red bean, crystal jelly, etc. - my favorite is avocado with large tapioca) and fresh squeezed sugar cane juice, as well as a large variety of Pan-Asian dishes.
You're also not far from Manny's deli (just off Roosevelt Road), hang out of Chicago politicos, which is famous for it's corned beef sandwiches, potato pancakes and enormous portions. Open for lunch only (about $10+). Personally I prefer the corned beef sandwich from the AP Deli (7th and Wabash) to Manny's; it's a dive but their corned beef sammie is delicious, $6, and in walking distance from your hotel. There's a Jewel foodstore nearby too (Chicago's major chain, at Roosevelt and Wabash, 2 blocks away) which has plenty of prepared food (fried/baked chicken, sides, sandwiches and salads) if you need a quick grab meal.