Relative Spending on Turntables and Cartridges

It seems conventional, at least at the low to mid-range of equipment, to spend much more for a turntable than for the cartridge. I'm wondering about the logic behind that. It seems to me that, once you've spent enough for a well-made turntable that with a good motor, sufficient weight and torque, and a solid tonearm that a cartridge upgrade is, relatively speaking, more valuable than a turntable upgrade. For example, I have a Rega P3 that typically comes with (in the package version) and Elys II cartridge. On mine, I know use a Rega Ania cartridge, which, as upgraded by SoundSmith, costs a bit more than the turntable. But the audible return on that investment has been enormous. I also have a Pioneer PLX-1000, which I initially used with a Sumiko Pearl cartridge. I've since upgraded, first, to a Hana EL, and subsequently to an Ortofon Quintet Bronze. Each upgrade improved sound quality (frequency response, transparency, detail, sound stage, etc.) dramatically. Perhaps I'm not getting everything out of the Bronze or the Ania that I would hear if I used them on higher-level turntables. But in terms of bang-for-the-buck, I've reached the conclusion that it is smarter to budget 50% each for cartridge and turntable than the prevailing norm of 75% for the turntable and only 25% for the cartridge (at least once your total budget reaches around $1000. Your thoughts?