My cats are indoor-outdoor, so flea meds are a must. I always used Advantage, then a new vet switched me to Frontline which did not work for sh*t (Newsflash: Frontline has lost its effectiveness in most areas of the country), so then I went back to Advantage.
Which works great, but at ten bucks a dose, it gets expensive when you have three cats. And Revolution, the flea med used by most rescues because it also treats ear mites and roundworms, is even more expensive.
Then I started volunteering for rescue groups, and discovered their fantastic secret:
Buy large dog doses and split them up.
Important caveat: DO NOT do this with Frontline or K-9 Advantix. ONLY do this with Advantage, Advantage II or Revolution. DO NOT do this with kittens under eight weeks of age.
It's pretty simple - The larger the animal, the larger the dose. If you can buy a larger dose and split it down, it becomes much cheaper per dose. You will need oral medication syringes (the kind withOUT a needle; you can get them at pet stores or in the infant aisle of drugstores).
Example: Advantage II, which was costing me ten bucks per .8 ml dose. You can buy large dog doses, at 2.5 ml, and split them into thirds for $3.33 a dose. (This is for cats over 9 lbs., btw.) Just open the capsule, squirt the dose into a little dish, and suck up three, .8 ml doses, one at a time, with the medication syringe.
See also: Revolution. I like Revolution because it also kills roundworms and ear mites. Here in the U.S., it's only available at your vet. But! You can buy it at Joe's Pet Meds online without a prescription. God bless Australia! You can buy 1 ml large dog (20 - 40 lb.) doses and split them into thirds for three, .33 ml doses. It's a little less than the recommended over-9-lb.-cat dose of .375 ml, but my cats are just barely over the 9-lb. mark, so I feel comfortable giving them a slightly lower dose. Again, open the dose, squirt it into a dish, and suck up three, .33 ml doses. (Advantage and Revolution have different dosages.)
Again: Do this ONLY with Advantage or Revolution. DO NOT do this with Frontline or Advantix. DO NOT give any topical flea meds to kittens under eight weeks of age.
I have been doing this for many moons now with no complications.