I think you'd have too much competition unless you had a lot of high end stuff, or even more low-end stuff, rented cheaply.
What I would suggest instead is to form a production co-op with a few partners, and offer studio space and room to set up green screens and edit bays on a DIY/ buffet table basis. Then you get local indie types, artists' collectives, etc. to rent the space out as and when they need it.
Something else that's an under-served market is a place that has special interiors generally unavailable these days: airline interiors and cockpits, airport concourse, hospital operating rooms and exam rooms, Dental office, school classrooms, bank lobbies, prison cell blocks, subway stations and cars, train compartments... get the idea? I'd find an old mall or industrial building outside of Chicago proper, maybe in the old steel mill area near Gary, Indiana, with the open space dirt cheap, and create these kinds of standing sets to rent out to movies, TV, Commercials (lots). You'd be the only guy in town for that stuff, and could thus usually name your price.
No. Bad idea. Too capital intensive. Equipment changes constantly. Rental gear gets abused by customers. You need a brick 'n mortar presence. You must have employees which is a money drain. Security from break ins is a major issue. I could go on....
Plus, if you needed any more discouragement, Chicago already has a saturated rental market.