Why does Custom Ink need an estimate on how many items will be in the order?
Because Custom Ink provides bulk discounts for every order, the number of items is one of the main factors in determining the per-item price. By providing an estimate of how many items your group will order, you are getting the most accurate per-item price.
It is important to note that if your group ends up ordering fewer items than you originally anticipated, your order will still stay on track. If you do not meet your expected quantity, you will see a balance due at checkout. When you pay the balance, your order will be complete.
If your group orders more than you originally expected, you will not have a balance due when you complete your order.