BDSA takes a unit weighted approach to calculating ARP. This protects our dataset from outliers that could either drastically increase or decrease the average price.
This means if 1 unit was sold at $20 and 10 units were sold at $15, rather than take the average $15 and $20 ($17.50) , we account for all the number of units sold at each price point and weight it appropriately, giving an ARP of $15.54, which is more representative of what price that item is being sold at.