Refactoring for DRY

[Barry Burd]

How's this version (of a simple example to introduce some of the functional programming concepts)?
Note: I'm not using type inference because my readers are better off learning about that later. Also, I'm using System.out.println in order to have a complete, self-contained example, but I'm saving that System.out.println call to the very end to avoid mixing side-effects with the functional code.
 
import java.text.NumberFormat;
import java.util.ArrayList;
 
public class TallySales {
 
  ArrayList<Sale> sales = new ArrayList<Sale>();
  NumberFormat currency = NumberFormat
      .getCurrencyInstance();
 
  public static void main(String[] args) {
    new TallySales();
  }
 
  TallySales() {
    fillArray(sales);
    System.out.println(currency.format(sales.stream().map((Sale sale) -> sale.getPrice()).reduce((Double price1, Double price2) -> price1 + price2).get()));
  }
 
  private void fillArray(ArrayList<Sale> sales) {
    sales.add(new Sale("DVD", 15.00, true));
    sales.add(new Sale("Book", 12.00, false));
    sales.add(new Sale("DVD", 21.00, true));
    sales.add(new Sale("Magazine", 5.25, true));
  }
}