I'm with VWbug08' on this. As long as you're being responsible with your finances, family, etc., there are much worse things to be doing with your money!
If I *had* to pick only one bass out of the ten I own, it'd probably be the Tony Franklin Fretless P/J. It's taken quite a bit of practice, but my accuracy has gotten pretty good and I've learned how to EQ it so that it can sound "fretted". It took me a while to realize that, just 'cause I have a fretless, doesn't mean I have to do slides /harmonic slides in EVERY song. If I were to add only one other bass, it'd be the Ibanez SR705... an amazingly versatile 5-string bass AND it's lightweight. I hope to never have to do this, 'cause I really like my Geddy Lee Bass, ICEMAN, Epi Thunderbird IV and Thunderbird V Pro, etc., etc.
I gig out quite a bit and, personally, I enjoy having a variety of basses to choose from. I have a mix of 4, 5, and one 6 string bass to choose from including a Dean Pace EUB. I've tried to avoid "duplicates", varying choices of woods, active/passive, colors, etc.
I have a load of fun switching mid-song between the Dean Pace EUB and a standard, fretted, electric bass. I usually switch my EQ at the same time to something with a little more edge.
Personally, I'd never want to go to a gig without two basses 'cause you never know what might happen. In one case, I had three basses and a bass player who was gigging down the street had broken an E string (HOW THE HECK DO YOU BREAK AN E STRING!?!?!?!?!). Anyway, I sold him the E string off of my 35" scale 6-string bass.
I will confess the easiest to play basses I own are the Ibanez basses and the two Fenders. The Epiphone Thunderbird Pro V has a 2" width at the nut and a thick neck... it's a bit of a bear! My 6-string 35" scale Ibanez is another one.