I've read a few recipes online, and it seems like Hawk Sauce requires quite a few flavorings. In all likelihood, you'll spend more acquiring the multiple flavorings than it'd cost for you to buy the flavoring direct from MBV (they sell Hawk Sauce concentrate flavoring) or just buy the pre-mixed Hawk Sauce.
Not tryna knock the idea, I'm always "for" cloning e-juices and experimenting with recreating flavors, but if you're attempting this just to save money you may have a tough time acquiring the flavorings for cheaper than it'd cost to buy the concentrate in bulk.