O'Fallon offers a relatively affordable cost of living compared to larger metropolitan areas. Housing costs are moderate, with fixed prices for city centre apartments and slightly variable rates outside the centre.
Dining out is reasonably priced, with a variety of options from casual to mid-range restaurants. Grocery prices are competitive, making it easier to manage household expenses.
Transportation costs are manageable, with affordable gasoline prices and taxi fares. However, the cost of a monthly public transport pass is relatively high.