I already have a bottle and I make my own salt/baking soda mix - both to avoid the expense of the packets b/c the salt costs almost nothing and to avoid the waste of all those packets. When I travel for just a few nights I do take the packets rather than my little salt set up but with how fast I'm using them I think I have a lifetime supply. When I need a new bottle I'll just pick one up at the drug store - no reason to pay for shipping.
Although I use the product regularly I won't purchase it online.
Good luck in making your decision.