I can't help but wonder where/what you buy if your DIY is twice as much as budget juice - my l liter of 100mg Nic that cost $50 shipped is over two years old and not even half gone, and I have been sharing it will my cousin for about a year now
Amazon sells PG/VG on the cheap, and flavorings can be had for well under $2 each while you find your recipes, etc
While you can spend quite a bit upfront, I figured out how to help one person get started for $30
I generally mix 250 ml at a time and it costs about $2 give or take. Think the most expensive one I make costs $2.80
I vape about 30ml per day
That's correct if you stick with Tfa, fw and maybe a fa or cap flavor here and there. And if you then have only a total of 1-5 % of overall flavoring in juices, keeping it to single or maybe a 5max flavor mix. Also if vaping 70/30 mixes and/or below and as many even vape higher ohm.
But I'm more the one that has multiple flavors at all time around the house, just like I've done with store bought, my mixes are mostly max VG, I use flv/hs/ooo/fafa/inw most of the time, a 10/15ml bottle is between $2.50 - $17.49 try buying the 4oz of that lol. I mostly have a overall flavor percentage of 12-18% in my juices, using more than 1 or 2 flavors. I know its my own fault and I'm not complaining, but pointing out that if you do go that route, at the beginning start up is higher than store bought juice that month. It will lessen after you've got the majority of flavors and truck loads of VG lol. Nicotine lasts me a long time as well, same as pg but VG and flavors, well you get the point.
Now multiply that by 3 because I don't just mix one juice for myself, I give it to my friend, then there's my husband and yeah we easily run through 60ml juice a day, depending what setups we using. And let me not even start with equipment needed at the beginning, sure you can make juices by drops or by volume with cheap syringes and I don't knock that, for me personally that didn't work.