1. A method comprising: receiving an item record that corresponds to a price-based value related to an item available to be transacted using a network-based transaction system, the item record including an irregular flag and location data that corresponds to the item; determining a threshold value for the item record based on the location data, the determining of the threshold value being performed by a processor of a machine; and setting a flag value of the irregular flag in the item record based on the price-based value transgressing the threshold value.