Yeah, you should be able to do Cafe Spiaggia for two for $100 or so.
$100 would also be enough for a blowout at Sabatino's, which can be wonderful in its oldschool italian-american way.
Cafe le Coq and Hemmingway's would be good if you want to stay in Chicago and want french. If you want french and are willing to travel, you might try Bistro Banlieue in a strip mall in Lombard or one of the many places downtown.
Do you have any preferences for type of food?