Magnesium oxide is useless orally if your goal is to get it absorbed into the body. Today we know this, and it is made as a LAXATIVE which it is when it remains in the bowel like it does. It is called Phillips Caplets.(the company that makes Milk of Magnesia).

GNC is vastly overpriced for what you get. They have missed the boat commerically IMO for the needs of people today.

However it IS difficult to get benfotiamine locally in stores. If you do find it, it will be ferociously expensive. Online it is very reasonable. I get my Doctor's Best form 150mg from Amazon. It lasts me 4 mos @ $13.99, you can't beat that for value!
Someone here did have a pharmacy order benfotiamine for them and it was way more $$ than Amazon's.... almost double.
http://www.amazon.com/Doctors-Best-B...I1N7ETK6YLBBNT

If you fear using a credit card online, get one that you recharge with cash only, and keep that for online purchases. That is one thing they are good for. Limit your cash on it for specific amounts. Or get PayPal, which has guarantees built in.

Being able to buy online is essential to quality supplement choices, and affordability. We typically use here non-mainstream items, but some of them are finally making it to outlets like Costco and WalMart...but slowly. You are spinning your wheels and wasting precious healing time at GNC etc, IMO.