This is NOT another CHEAP/VS/EXPENSIVE thread. Just to be CLEAR.
Ah, yes, but it will inevitably end that way, intended or not...
But that said, the problem with these threads is always the same: it depends on what "better/nicer" means. In general, that means different things to different players.
For me, "better/nicer" is mostly functional. For example, I prefer a very low action up and down the whole fingerboard. I also need a jazz bass dimensioned neck and a bridge PU on the bass. I also no longer require more than 4 strings.
There's more, but that's an example of one set of items that go into my definition of "better/nicer". So to get that, I have, over the years, found that I need to spend somewhere in the neighborhood of about $1500, just as a general ballpark figure.
My Fender jaco artist basses are the most expensive I've ever bought to get a jazz dimensioned neck that I can setup with very low action up and down the whole fingerboard.
I won't go into the lines vs no-lines thing, except to say if I do ever get a 3rd or more bass, an unlined fingerboard will be a hard requirement. Or it'll just be a fretted bass.
Other players may have other requirements that make up "better/nicer", and for a lot of folks that's primarily cosmetic. So they're willing to pay quite high prices for basses that just look a certain way. Others are very particular about the types of wood, so they'll pay a premium for whatever type of wood it's made out of. And many don't care what it sounds like or how hard it is to play. Some folks are collectors and buy them as art pieces. and don't play them much at all. And etc.
I, OTOH, don't care what wood my basses are made out of, so a "better/nicer" bass for me may end up as just plain jane Maple on the neck, and tabletop Alder on the body, with no top and don't care about the color or finish. That may be a crap bass to someone else, though.
Anyway, you get the idea....
L