Back to the OP, I think an expensive bass is where there is a bass i want, but immediately think that perhaps I should wait and see if I can pick one up used, rather than just buying it new. This was me when I wanted a Rob Allen. As to the actual level of money, this will always vary from person to person and we shouldn’t judge others by what they consider expensive/cheap.
That aside, upper level instruments seem to be outstripping inflation by some measure. My first ever custom bass is coming up 10 years old, so I dug out the invoice, did the inflation calculation and it should now cost roughly £250 more than I paid for it. Even the basic, off the shelf, version is way beyond that. If I go back to aforementioned Rob Allen, these have doubled in cost over a 15 year period and I mentioned my surprise at the cost EBMM basses earlier in the thread. Manufacturers seem to having a laugh with their premium instruments.