The. Problem is diy juice isn’t a lot cheaper if you don’t diy yourself. Thats what makes it cheap. Me I just use single flavoring sets so it’s REALLY cheap, but the impression I get is it’s either cheaper OR better, not both at the same time. The stuff is really easy to do. Easier than cooking for the quick&easy stuff, and about like cooking for the better stuff. For the better stuff you need a few tools, some of which you probably already have, like a cooking scale. There is also a half measure that inwara does called a one shot, which is premixed flavoring you add nic and base to. It’s usually a bit cheaper than retail juice, but more expensive than the mats alone. Sort of a hamburger helper thing. Thats even easier than quick&easy juice, but you pay for the convenience.
A description of flavorings: (you may not care)
Caution: this is the area where a lot of cigarette manufacturers make their hay by hiding sources and conflation
“best” isn’t always safest. It’s really important to avoid oils of any kind. The way flavorings work is you take,say, an apple, which has a few thousand different chemicals in it, and you pick 10 or so that together are the most “applish”. If you picked all several thousand you’d have, well, an apple. So you leave out the ones that aren’t “applish”. Some of those things will be oils. You don’t want to use those even if they work better. Dydactyl is a famous butter one, but it’s an oil and as a result is dangerous. It has a terrific butter flavor, and eating it is fine. Breathing it isn’t though.
Another problem is volatiles. Some stuff is really unstable so similar things that ARE more stable need to be chosen instead. This is also sometimes done for “yeah but it’s an oil”. So there is a limit. Some stuff is safer but not as tasty. Some stuff is the reverse.
A third problem is temperature (this is why temperature control mods exist) Everything (and I mean EVERYTHING) breaks down when exposed to a high enough temperature. And it usually breaks down into something else (sometimes it just reforms into the same thing again, but sometimes it doesn’t. Usually this is well above vaping temp, but sometimes it isn’t. Also there is stuff where part of it can withstand vaping temperatures but other stuff will turn into “something else” and that something may be dangerous. So you also need stuff that is resistant to heat. You can usually tell because there is a massive flavor change, and vape juices are usually made of stuff this doesn’t affect (and is why FDA baking safe is important. FDA baking safe is good to 450f or 223c where a cotton wick flash burns anyway) but some of the tastiest stuff doesn’t work when heated. A vape with a wet wick generally doesn’t go over the boiling point of the base which is below 100c (I forget how far below) But some of it that is actually touching the wire will go higher.
In my state premix juices have to pass a heat test that shows they are safe, so you CANT buy premix juices in my state that have this issue. The testing was expensive.