Add 320px to the canvas height for each product added
Next Item = 2640 + 320 = 2960
Next Next Item = 2960 + 320 = 3280

To add 1 row: add 374 px to canvas height
Next Row = 941 + 374 = 1315 px height
Next Next Row = 1315 + 374 = 1689 px height