What Dee said.
Premium juices don't exist, ejuice is just carrier and flavoring, all pg is harsh, has more th and bite to it, less vapor, this gives some the impression that it's cheap, vg is syrupy, smoother, less bite, more vapor, giving some the impression that it's higher quality. I like all pg for th and bite but it doesn't like me, dries my mouth and lips out too much so I go with 40% vg.
You can get fancy, grow your own organic herbs and whatnot, otherwise it's ready made off the self flavoring with the likes of Lorrans, Capellas, Flavourart, TPA, etc.
The tobacco juices from China are very good (they invented them) they make their own flavors, but the juices tend mostly to be pg.
By far your biggest hurdle will be dealing with all the hype and hoopla surrounding some USA vendors (only in America right) ..beware of terms like - 'the finest ingredients' and 'hand made'....yeah sure!...try pouring milk into your coffee using your feet.
Good luck, do some reading.
I also have to disagree with some of this statement. Todd at Vaperite certainly does make a "premium" USA made product. He goes through the process of extracting his own tobacco flavor for his tobacco juice. He also does offer completely organic juice, using VG and certified organic flavors. Yes, it costs more than Dekang, but it really IS a superior product to Dekang.
Now, if you really do want the least expensive way to get juice, I agree with the DIY. You can make 30mls for less than a dollar!