Is there usually a dramatic difference between $5k and $10k cartridges ?

The answer is yes but usually with a highly transparent audio chain. 

$30k table, $15k arm, $25k phono stage and you may be ready for $10k cartridge. Or perhaps it is $40k table and $10k arm. Whatever. And don't forget about tonearm cable, it is the most important cable in the entire chain. Oh, and motor controller for the table. That would be excellent though still not top of the line analogue front end.

OP,

I agree that this proportion, in general, makes the most sense.

That is about what I have and am waiting to for the right time to make the jump.

However, a couple of my friends have put a $12K cartridge on a ~ $10K table / arm and ~$10K phono stage. The difference was very amazing... of course they had very high quality speakers / preamp / amp. So, it is just like the rest of high end audio... there are rules of thumb that sometimes can be broken.

In general, I have found if you have all really great components... sometimes you can drop in something of much greater or lessor value and the outcome is surprisingly good. But I wouldn’t build systems like this. You always want to put the odds on your side.

ghdprentice, of course.

I once put $2k power cord on $1k integrated amp and it was much better compared to $500 power cord, let alone $100 power cord.

Conversely, I evaluated 6 different power cords providing power to the bias supplies of my Sound Lab ESLs.  I did not expect to hear much if any difference, but I did hear a hardware store power cord (the stock cord. provided by Sound Lab) come in second to a ribbon type power cord from Maple Shade, which was by far NOT the most costly of the 6 cords I evaluated.  LIkewise, one ought not to generalize that cartridges can in any way be ranked for SQ according to cost. You can do it, but you will be ignoring some superb cartridges.