In what is a limited-time offer, PayPal Digital Gifts is selling Under Armour gift cards, $100 each, for $90. If you have certain business cards that offer 5x points at office supply stores, this purchase should also trigger that as well for a nice extra bonus off.
I am a huge Under Armour fan. In fact, not much of what I wear is not Under Armour! We typically see a good Amex Offer pop up around this time of year but, if I recall, the last one did not count with a gift card purchase. So, if you want a gift card, this may be the route to go.