My impressions of the members here is that the majority of us are past our midlife crisis and are pretty much financially stable.
Many of us have, or have had, high end equipment costing thousands of pounds which realistically won't pay itself off from our income as musicians, however we are at a stage in our lives that we can treat ourselves to quality gear in our hobby/interest.
Whether we "need" more than one bass is immaterial - I can't take my money with me when I die so I'm going to do what I "want" to do with it and spend it on the most important person to me - ME!!
I don't drink, take drugs, drive a fast car or bike or have wife/children to spend it for me - my gear is possibly my only real eccentricity though to be honest I do hoard a lot of stuff I probably don't "need". Not hurting anybody else though...
If I want to buy another bass, I will!!