I know there is no one answer, but I am thinking that owning fewer basses means that I can learn more out of each one instead of owning a bunch of basses I rarely touch. Frankly, most folks who have multiples, have one or two favorites that get most of the playing time.
As I said there is no one answer. Some people love to collect. Some may have a few basses for very specialized uses. As for me, I only have one gig, and I suspect anything that stays in tune will work for me.
Interesting thought... I'll add a few thoughts.
I currently own 7 basses and 4 guitars. I'm a bass player who started on a string bass and moved to electric, and have dabbled in guitar here and there, not a guitarist turned bassist. All of my instruments have a specific purpose. The basses:
- A straight up '79 P with flats
- A MIM PJ (my main bar gig bass, it's a lightweight alder example)
- An ash bodied active PJ (main backup and to fake MM 'Ray sounds, too heavy as a main)
- A Squire fretless Jazz, box stock, that's a surprisingly good instrument. ($200 CL find!)
- An Ibanez fiver
- An acoustic bass guitar
- A P with heavier strings (rounds) and properly set up for D-G-C-F
All except the ABG are setup to play pretty similar, so there's not much to get to know or get used to. All of my Fender variants have Jazz necks. Most have distinctive sounds, so I keep them around. I do play #2 and 3 most, and the others where they fit. A few bars into a song, I'm plenty comfy on any of them.
The guitar arsenal is similar, an HSS Strat with coil splitting on the Dimarzio Super Distortion H and a blocked trem, an HH Tele with set neck and splitting (Fakes Teles and Les Pauls! ;^)), a 335 style, and an acoustic. They're all very different machines.
I COULD survive with two basses or one guitar, but the benefits of having a selection make me happy and switching is a breeze. What I've got is far from a collection, as most anything other than the '79 P is probably depreciating and they all get played as needed. I don't see added time spent on maintenance, as I'm comfy doing setups myself and I can do them quickly. The two PJ's probably draw the most maintainence time, as they get played the most and require bright strings.