Gift cards? Can you use three on a order?
ETA: If a purchase made with a Gift Card exceeds the amount of the Gift Card, the balance must be paid by another valid payment method (i.e., credit card, debit card, additional Gift Card(s)).
Gift cards are applied via promo code. Only one promo code is allowed per order. However, if your gift card exceeds the amount of your purchase then the remaining funds are automatically applied to your account as a credit. Then on your next order you can combine the account credit with another gift card.
So for example, if your first order is worth ~$20 with a $75 GC then the account credit will be $55. You can then place a second order of up to $130 ($55 credit + $75 GC applied). You can keep on doing this method to build up the account credit to the necessary amount.