Since I posted this topic, I did some research on the Capstar. What I found is the main ingredient in it is nicotine!
Recently, I bought generic Frontline, and it didn't work. We had the fleas all over again. I've managed to get Frontline Plus cheaper, through Ebay. HOWEVER, you really have to watch when you buy from there. People that say they are selling "kits" usually are selling generic Frontline Plus. I've discovered that you can buy the kind for larger dogs, 89-132lbs, and get 8 doses, but it seems to lose its potency after about 4 months. That works perfect for me, since it looks like my son and his cat, Abraham, 2 yrs old, are staying permanently.