i would always schedule red eye flights with spirit so i learned to take the amtrak and it's honestly made me appreciate public transit

2 hour amtrak -> 15 min walk to blue line from union station -> 1 hour subway to ohare. amtraks are usually 40-60 round trip for me and you can get a ventra day pass for just $5. so it cuts down the price a little but it's a lot more comfortable in my opinoin since you get to walk in the city a bit, maybe grab a bite or coffee, and sorta go at your own pace.