budget split between cart and phono stage

Cartridges are transducers, like speakers and microphones, so their sonic variations tend to be much greater than electronics. My advice would be to find a cartridge you like, and use whatever money you have left to buy a phono stage, rather than going in with a preordained ratio.

Mr. Campbell is right about the challenge facing designers of phono stages. (He didn't mention RIAA equalization, which not every maker does equally well.) But the differences among phono stages are still dwarfed by the differences among cartridges. That's why I think if you find a cartridge you really like, and its price means you have to settle for a less expensive phono stage, you're probably still well ahead of the game. (OTOH, I would not assume that a more expensive cartridge is necessarily a better cartridge. Keep an open mind.)