I buy mine from LLMedico. They give you 5% back on each order, too. The last case I had auto shipped was $52.24 with free shipping. They do ship them in the original box. I usually get them in a day.
To add to this, I have ~7$ in my rewards account. I am not sure if using that would drop me below the free shipping threshold. My plan was to save up enough and get a free case later on.