Earlier quoted context omitted.
The mark up for juice at most vape stores is obscene, yet still manages to be cheaper than regular cigarettes. $15 for 30 mL at my local store, that lasts me on average 15 days. So it's still roughly half the price for a half pack a day smoker and 1/4 of the price for a pack a day smoker (assuming a very generous $5 a pack). If you mix your own juice you're approaching savings that are better on an order of magnitude…
I highly recommend Vapejoose, they have 120ml bottles for $23.99, sometimes $20, and they offer free shipping over $50. Three 120ml bottles last me close to an entire month. Local stores around here are also a rip-off (near Austin, Texas).
That's more than 10ml a day! I know you're going to disagree and try to convince me otherwise, but that is an INSANE amount of liquid.