Price is one consideration, but so is quality. Getting an inexpensive product that isn't truly beneficial isn't a good deal. So I suggest you start by looking at quality pharmacies.
You're getting a prescription from your doctor, so start with the pharmacy your doctor recommends. Ask your doctor if they can recommend more than one. Ideally, your doctor should be familiar with the pharmacies because she should have a lot of experience with prescribing compounded medications. If she doesn't have that experience, you might need to see someone else.
Go to your local pharmacy and ask their advice based on your specific compound. Do some searches online. Some pharmacies specialize in certain compounds. For example, I take one now from an excellent pharmacy, but I might need a second compound medication soon for a different condition and that pharmacy simply doesn't make compounds of that type. So at this stage you should be looking for pharmacies that simply make your compound. Get a list of options first, then look into quality and price. Check in with your state's Department of Public Health (or whatever it's called in your state) for quality reviews and lists of options.
More than anything, I'd suggest asking around in patient groups both in person and online. Facebook, Yahoo, and Twitter all have a lot of patient groups with people from all over the world. Take their advice with a grain of salt, of course - you don't know them - but consider what they have to say. I've gotten good recommendations for doctors, treatment, and resources from patient groups on Facebook, and an incredible amount of information from Twitter. In fact, most of what I do on Twitter is health-related.
You might also want to consider posting your medical condition on the forum here. Maybe others with the same or similar conditions have experience with compound medications and can suggest pharmacies for you to try.
Good luck!
