Monticello, IL Prices for Houses for Sale AVERAGE 248,100 -20% MEDIAN 199,950 -34% Relative Price (per sqft.) PRICE Listings of Monticello Homes for Purchase ACTIVE 6 -25% NEW 4 -67% Market Duration of Homes Sold DAYS 66 +66% Local Statistics Population 5,557 (0.00%) House Size (sqft.) 1,785 (-5.78%)