Impossible question to answer.
My wife hates what I like and vice versa. All about your preferences.
Many "premium" juices are made in the same factory on the same production line as many others. As long as the juice is made with top quality nic, PG, VG and flavouring, the only real difference between a $9.99 and $29.99 30ml bottle of juice is good marketing, cool packaging and a great recipe. Most juices use the same 4-5 flavour brands, but blending a bunch of different flavours together to taste great isn't as easy as it sounds.