Most expensive bass I owned was a Dingwall ABII which cost £3,000
I loved playing it, loved the sound but couldn't relax in case I got a ding in it.
As for cheaper basses, it's not that I don't look after them the same, I just don't panic that much if I get a nick in it.
Unless I became exceptionally rich and could afford to replace a Fodera at will with the ease of a financial speedbump I wouldn't spend that amount of money again.
About £1,000 is about all I would invest, any more and my worry level rises too much. But that's just me, others may say it works for them.