Cook County reassesses on a triennial cycle and appeals are a normal part of ownership. A recent reassessment can move a building’s tax line materially between listing and closing; read the assessment history, not just the current bill.
Condominium assessments and deconversion politics matter in the older high-rise stock. Illinois preempts municipal rent control, so the letting model is unregulated in a way New York’s is not.
The North Side lakefront, the West Loop and the South and West Sides are separate markets with separate liquidity. National price averages describe none of them.