I will say that I know a lot of bow tutorials will tell you to wrap the ribbon completely around the alligator clip...
I have found that it is MUCH easier to wrap it around the hinge, and top section only. Leave the bottom of the clip (the part that will be hidden under hair...) ribbon-free. It is MUCH easier to put the pointy, smooth clip in hair than to fight with a flat surface. I actually wound up cutting all of my DD's full-ribboned clips so they were pointed, because it really is much easier! Plus, it will save you a couple of inches of ribbon per bow. :)
I would hit up the local craft stores every couple of weeks, and check out their clearance bins. I went to Michael's the other day, and their bins had spools of ribbon for $.25! :)
Oh! One more thing... I have made some bows, and instead of putting them on a clip, I will just leave a little elastic loop. That way, I don't have to buy so many clips. I just slip it on an empty clip, and voila! It's also nice to be able to slip it onto a bobby pin for smaller ponytails, or even over a button as an accessory to a shirt. :) I have even looped rubber bands through them, so that they are a part of the pony tail instead of being clipped in. (great for more active play...)