Asking for members blessings on Nagaoka MP 300 purchase

Big admirer of Nagaoka cartridges, but I advise get the best one you can afford in the MP series.  There's not that much difference in cost last time I looked. (I just bought an MP500 on a lark.)

Nagaoka's are moving-iron cartridges. So are USA- made Grado's. I'd get a Grado at your budget price. 

I have the MP 500, have not heard the 300. But for a little extra you will never say what if. Amazing detail, wonderful separation. Perhaps the best bargain in analog.

So they have a lightly used MP 500, which I believe was a return with very few hrs. I actually can get it for less than the MP 300 new. The 300 is supposed to be a bit warmer, but will does up some detail to the 500. And my understanding is the 300 is a bit more forgiving of less than perfect VTA setup. So it's certainly not the money. It's more about a bit more warmth and allowing the slight margin for error with less than prefect setup. Funny... of all the Nags, I found the least amount of info on the 300. I think that's because most who can shell out for the 300 stretch a few more bucks and get the 500.