If you have a Hobby Lobby near you, they stock 100' bundles in numerous colors. It's $8.99 for a bundle, and they often run pretty good coupons on their website.
Just take a woman in there with you, and look really ticked off while you're grabbing the paracord, you'll be fine.
That looks cool. Where is a good place to find instructions on making those type of things?
If you prefer online shopping for supplies, I've found that the Supply Captain is my favorite for 550 paracord. The absolute widest & best selection of patterns & colors. $7 for 100' hanks.
Supply Captain: 550 Paracord
The possibilities for projects is endless.