This is just my opinion and you are going to find exceptions with almost all I say but here are some things that make a bass high end. But alot of high end basses have atleast some of these things:
Expensive - usually about $1500 or more new. (Example: Warrior/ Exception: Peavey Cirrus, Stingray H)
Custom Options - You can order the bass with plenty of options in every category, not just finish (Example: Carvin/ Exception: G&L Tribute, Rickenbacker)
Not mass produced - (Example: Wal/ Exception: Stingray, USA Fender, G&L)
Demand outweighs supply - (Ex: Rickenbacker/ Exc: Cirrus and G&L again)
Super tight fit & Super good fretwork & high attention to detail - (Ex: Zon/ not really any exceptions)
Sometimes have a neck through option (Ex: Spector/ Exc: a gazillion of them, but I am am saying that those who do usually are high end.)
Sometimes have a fancy top option (Ex: Warrior/ Exc: a gazillion of them, but I am am saying that those who do usually are high end... but their are exceptions to that nowadays too so...)
Usually are not on an assembly line but are assigned to one person or one small group by each individual instrument. (Ex: Alembic/ Exc: Stingrays & Carvins are probably on an assembly line.)
And the big one that is going to turn this into a pissing contest - Are usually not made in 2nd or 3rd world countries. This opens up a huge debate because I am not sure if Korea is considered 2nd world anymore, well not to me anyways, and China is well on it's way. Let's just say high end basses are usually not made in Indonesia, China, Mexico, Taiwan or somewhere where there is cheap labor or machinery and it is being used to produce the basses. I am DEFINITELY sure that somewhere in these countries you are going to find a custom shop quality maker, but usually 99% of the basses out of these countries are not high end, for the fact of the sheer volume of mid/low end coming out of them. There just has to be a high end builder somewhere in Mexico and Korea. High end basses usually come from economically developed countries, but even if basses are from developed countries, that doesn't mean they are high end... that is VERY certain. Also as always the exceptions... Czechoslovakia and Italy are places with a very deep tradition of luthiery and have cheaper labor than most more developed countries. It is entirely possible (or atleast used to be) to get high end work from those places for fairly cheap coin. I am sure their are other places like them too and their may be newer ones later.
I am sure you guys will find all kinds of other exceptions because this term (hi-end) is so vague. Terms that I think are more concrete are handmade, custom built, vintage, made in the USA and stuff like that. Another really vague term is boutique IMHO. There is some overlap of hi-end and boutique with some of the more concrete terms.
So I think that all the above basses I mentioned are high end... yes even the G&L tribute (I know that my threashold for high end is probably a bit lower than most of you.) But this is totally IMO, there are levels of high end bass... yeah some that are just ridiculously high end like Alembic, Fodera, MTD, and some of the lesser known builders who will build you ANYTHING from scratch. Then their is Sadowsky, Valenti, Fender Custom shop, Modulus below them in a 2nd group. Then their is Cirrus, G&L Tribute, American Fender in my third group. Since it is a spectrum and it is subjective to each person it gets jumbled real quickly. A stingray is somewhere between the 2nd and 3rd group, and a Wal is somewhere between the 1st and 2nd group. See! Now we have a mess.
Then we got mid-grade instruments such as Schecter, some of the better Yamahas, Danelectro, The Bass company (even though they are inexpensive.) Usually midgrade instruments are fantastic but may be lacking in some area that can be upgraded (Ex: electronics) or worked out (Ex: fretwork,) or they may just seem very average in some way. Some might argue that Carvin or USA Fender goes here, but I can't see how G&L would (I've never seen anyone upgrade any kind of G&L, and if so it is not normal.)
Then we got low grade instruments such as SX (but a GREAT value I might add,) Jay Turser, Brice, Italia, Epiphone, and Daisy Rock. Many of these are decent basses and decent or better value.
Then we got the junk brands such as Johnson, Squier (the old ones folks,) Tennessee, AXL, Washburn (post 1990ish,) Rogue, and First Act. These usually can't be made beyond just passable or just ok without replacing all but the strap pins, or atleast rebuilding or reassembling with alot of work and care. But sometimes they get lucky and their are individual basses that are fantastic.... not the norm though!
Of course even the hi end makers have their turds too. I once played a junky Warrior and a junky USA Fender and many other highly regarded brands, but it's also not normal.
Then we got brands that are really all over the place since some aspect of them is so polarizing. Wishbass for certain! Warwick to some extent (I think because of the neck profile.) Then we have brands that have such a wide variety of grades within the brand (including some of the ones I mentioned... Yamaha, Peavey, Fender, and many of the bigger manufacturers.) Then where do we put Godin? Middle or high end? And where the hell does Gibson go besides overpriced (yes this is my personal opinion.) Most people don't know this but Schecter, Yamaha, and First Act all have extremely high end custom shops. How about brands that changed over time such as Washburn, Fender between different ownership groups, and Tobias same as Fender? And how about the 2 no longer affiliated Tune companies with identical logos and designs? Is a CBS Fender REALLY high end? (Don't even go there PLEASE!) There definitely are some basses that will be harder to group, even personally.
Does the low end tone cancel out the high end price? How will this affect the price of tea in China?
