I was referring to amps and cabs, not instruments, as that's what this discussion is about. I agree that budget instruments can work very well. I have a couple. They needed to be fettled/tweaked to get the best out of them, but I do my own set-up, so can afford to take the time to do it.
Like you, I don't think there's any substitute for spending proper money on amps and cabs, and particularly cabs. You can save money on amplification, especially if you buy used and don't mind carrying a bit of weight, but you need plenty of grunt. Phil Jones commented once that bass is the instrument from hell to amplify. I think he's correct (fwiw, I use PJB cabs, but I run a number of them - four or five of his 4x5s and enough amplification to drive them properly)
I particularly agree with Alex's observation that the trend towards smaller, lighter rigs has exacerbated problems for bass players. A bass places stiff demands on gear. We need to shift air, do so cleanly and have enough power at our disposal to ensure its working well within its capabilities. Otherwise, it will struggle when pushed, like that little city runabout does when you drive it hard on the motorway.