Well...first, what you are wanting to do is illegal but not really enforced at this time. So I would suggest exhausting options with your Dr to let them know you cannot afford and if physician cannot help there programs at Lake Superior Health, SMDC and I believe St. Luke's where pharmacist help find cheaper alternatives for patients in conjunction with their physicians. Some of these programs are free and some have a small charge (which some insurances cover).  

Still, I fully understand why people look online since our system is too expensive for brand name medications. So, when it comes to online I would try Canada since its FDA is very similar to ours in safety and regulation. However, just shopping online it's impossible to tell what a pharmacy is actually like. Is it just claiming to be in Canada or is it a illicit pharmacy in Canada doing a sham business there? (too many sham pharmacies to be caught by CA authority). Anyways, I advise trying to go visit the pharmacy you are going to buy from in Thunder Bay. You could actually tell if it's a legitimate place, then do online or phone/mail ordering from then on. Remember, it will likely only be cheaper for brand name drugs. Generic drugs are usually cheaper here just shop around local pharmacies for cheapest generic prices.

I would go to Canada if I were you.

It's technically illegal to buy from other countries/import prescription drugs, but that's where it's cheaper. You will not find much cheaper brand name drugs in the US unless they are fake.

I always use Medco.com.  They are prompt, inexpensive, and if I am not mistaken, they offer free shipping.

See website, while it is most definitely to import drugs for personal use no one is prosecuting and coming after individuals, and quite frankly the canadian FDA is just as good as ours in most every respect and sometimes better than ours just depends on the issue at hand. So main challenge when buying online is making sure you really are getting drugs approved for canadian consumption and not counterfeit. 

Law Governing Importation
-The FDA regulates the sale of drugs under the Food, Drug and Cosmetic Act of 1938, which forbids the sale, distribution or importation of misbranded or adulterated drugs, unapproved new drugs and counterfeit drugs. A provision prohibiting personal re-importation of U.S.-manufactured approved drugs was added by the Prescription Drug Marketing Act, passed in 1987. 
Current FDA Guidance
-Under the General Guidance Section of Chapter 9.2 of the Regulatory Procedures Manual, the FDA has the authority to not take action against personal importation--generally a three-month supply--of unapproved drugs when the intended use is for a serious disease for which effective treatment is not available in the U.S.; the drug is not commercialized or promoted to people residing in the U.S.; the drug is not considered to represent an unreasonable risk; and the person states in writing that it is for personal use and provides information about a U.S.-licensed doctor responsible for his treatment or shows that he will be using the drug as part of treatment begun in a foreign country. 
Importation under the MMA
-A provision of the Medicare Prescription Drug, Improvement and Modernization Act of 2003 would have allowed importation of prescription drugs from Canada had the HHS Secretary certified that such drugs would pose no additional risk to public health and that U.S. consumers would realize significant cost savings from such importation. However, an HHS task force charged with studying the importation of drugs under the at found that the cost savings would not be significant, that the current system of importation (primarily through Internet pharmacies) poses significant risks to consumers, and that it would be both very difficult and expensive to implement an importation program that could guarantee the safety of drugs purchased abroad. Such drug importation was not permitted as of April 2010