We are always amazed when we purchase our monthly flea/heartworm meds at how expensive they can be. Mum usually tries to find ways to save some bucks on stuff like this and she's used some sites that have discounts - getting the script from our wonderful vet, and ordering online. Usually works pretty well! And they don't really mind.
And she even uses an the Internet to help her save on her meds when she needs them. (Not that she usually does, but...). Mum even has used an Online Canadian Pharmacy to save some bucks sometimes.
So what do you all do? Do you buy your heartworm meds from your vet, or do you look for ways to save some bones too, ordering online or other ways? We sure would be interested in knowing!