Yep, I'm vaping about 2.5 ML per day.
After a little shopping around, hands down TastyVapor is the most cost effective vendor.
Get 1 ounce of 48 MG juice, and 4 ounces 0 MG juice of the same flavor.
Mix them together, that's 5 ounces of 9.6 MG.
That's 5 ounces for $30 + $5 shipping
BiffRoco has the right # for ML per ounce, but Tasty Vapor overfills their bottles, so you can just say 1 Ounce = 30 ML.
After a little math, That works out to $0.24 per ML or about $0.60 per day.
Not bad at all.
The math will change a little if you need higher MG, but it's still very cost effective.