I've been known to spend far too much time and money on cheap basses, I'm literally flatting and polishing a refinished 80's Kay bass between BC browsing sessions. I look at it as a hobby, I don't do any of it to make a profit and I'm well aware that some of my basses would make a fine loss if sold.
Other people pay thousands per year to push a trolley around a golf course, digging around in the undergrowth and whacking balls into lakes.
As has been mentioned, as long as you go into it with your eyes open and don't expect a bass to be worth the sum of its parts, then knock yourself out and enjoy the process.