hhmmm...I've only had good luck with Frontline, but I haven't really tested all of them. Maybe you can hunt on the internet for a discount distributor. That may help the costs out a bit. Fleas can be sooo annoying, it is just best to use the best. Hopefully, you'll be able to stick with Frontline. My vet has a program that gives discounts when you buy larger quanities. Chloe is only a little girl, but when I get her flea meds, I do it for the year and it ends up costing about $130 AND I get 6 free! Bestest of luck!