So i recently “upgraded” from a sigelei 150w tc with tfv4 to an Smok al85 mini alien with a baby beast. Im well aware this really is not an “upgrade” i just needed something that better suits my work day and being away from home. I very much am enjoying the new set up minus the small tank capacity, not a huge deal to me though. A couple weeks prior to aquiring the alien, i got ahold of an rba for the tfv4. Love it. My issue is that this tiny tfv8 baby seems to be sucking up more juice than my tfv4 with either the rba or stock coils. This doesnt make much sence to me it being smaller in coil size, vaping at similar ohms and wattages. Prior i was using about 15 mil juice a week with stock coils, and no more than 30 mil a week with the rba (tfv4). The v8 baby beast is blowing threw a 30 mil of juice in a matter of about 5 days maybe even 4 (which sounds normal for sub ohming). I don’t feel as though my vaping has changed as far as usage. I have dropped from 12 mg of nic to between 3 and 6 depending on availability and what tank i was to take to work for the week. Maybe the higher nic was helping me conserve my juice i dont know, the difference seems to be to drastic to be the case. I use between 22 and 28 watts and .4 to .6 to .8 ohms stock and rba coils for tfv4, and just stock coils for tfv8 baby beast (no rba for that yet but planning on getting one) My question is PLEASE HELP ME CONSERVE JUICE! At $20 a 30 mil i need to find a way to conserve. Weather it be going back to the tfv4 rba or maybe buying another sub ohm tank altogether that is known to be efficient, as well as a great tank for flavor. Im just trying to make this a little more affordable. Thanks! Any and all input welcome! 
You could learn to make your own juice. This is a DIY e-Juice site after all.
Gotta start making your own and stop buying overpriced commercial liquid.
I enjoy vaping at 1.5 nic and it’s easy for me to go through 30ml a day. No way I could or would pay that for subpar commercial juice that mostly irritates me instead of making me feel good.
Your weekly juice usage is a daily thing for some vapers that mix their on juice. As far as your set up I can only comment on the TFV4, but I only used the RBA and it was my 1st tank that really drank a lot of juice. If juice consumption become too much of an issue, maybe you can consider making your own juice. It’s a little tough from start, but it a pans out in the end.
Well seems making juice is the median. So how do i go about doing this, i have a couple recipes for clones, so with the minimum ammount of materials and lets say starying with like 3 to 6 “flavors” excluding nic, pg and v.g. where is my starting point and what do i need at minimum? Minimum average price?
Start with the beginners thread, there are well thought out guides on getting started along with tip for getting the best bang for your buck. The info is all there for ya to get started.
One of my more expensive recipes, that i vape daily, costs $20.08 per liter, plus the bottle. Another is $22.11. These are multi flavoring mixes with 2mg nicotine.
I dont even keep track of how much i vape, i vape as much as i want when i want.
This is a definite possibility, lower nic making you want to vape more. But like everyone else said, get on the mixing train and it won’t matter. 
I probably vape 20-30 ml per day and I’m spending mere cents on it.