One of the things with Oak Lawn is that it is so big that internally and surrounding areas are both increasing and decreasing. There are brand new million dollar homes going up but there are also neighborhoods with tiny lots and 2 bd/1 bth homes.
In general, Chicagoland is down to earth with lots to offer. You don't see high and low swings creating a bubble that could burst. But you do see changing neighborhoods which affect value.
I hope this helps.