The other really important thing that people don't understand is when to test your cat's blood sugar. You should have your vet thoroughly explain this to you, as pet owners often make the #1 mistake of adjusting their pet's insulin based on what their pet's blood sugar/glucose is. If you test it at the time of when you give the insulin, it should always be very, very high - this is "normal." Depending on the peak effect of when your insulin works, the blood sugar will be totally different and you should never adjust this without your vet explaining how a blood glucose curve works.
Hope that helps!
You do want to make sure you get reliable materials though. Various studies I have seen but can't quote tend to find variable readings with various glucometers. You tend to get what you pay for so make sure your veterinarian is okay with whatever glucometer you are using.
If you get accurate results, you will be able to control the diabetes better, your cat will be healthier which saves money in the long run.
Your cat is fairly young to be diabetic. Your vet may have talked to you about this already but a high protein canned food diet and getting him to an appropriate weight helps greatly in diabetic control. He should also be examined and have blood work done more than once yearly, at least every six months. Proper diabetic control can lead to remission of the disease.
Good luck with him.
Judy Karnia, DVM
Scottsdale Cat Clinic
In googling "blood glucose test strips", I found several websites which offered test strips and glucometers at varying prices (ie.http://www.diabetesnet.com/test_strips.php). Since your cat is going to need lifelong care, it will pay for you to shop around.
Kimberly Coyner, DVM DACVD