Benefit of low output moving-iron Grado ?

Well, gosh. After reading such things as the Wikipedia article on cartridges (duh), and some various debates on forums... I feel that it is no wonder that nobody has responded yet! I am a little better educated on the matter now, so perhaps I can restate a few things. Apparently moving iron is pretty much a moving magnet in slightly lighter clothing. Therefore, I can only assume that Grado offers their select MI cartridges in both .5mv and 5mv versions, at exactly the same cost; so that the clearly subjective matter of choice between the two would depend on such things as the phono stage and other equipment, likely purchased to accommodate personal taste in high or low output cartridges.
My phono stage is a MM "phono card" which fits into my integrated 2010s Exposure amplifier, and is manufactured as an option by Exposure. I could buy the MC version for about $250 (would the MM phono card I've got handle a .5mv MI cartridge?). Maybe a relatively inexpensive $250 phono stage is better suited to a high output cartridge anyway?
My turntable is a Music Hall mmf 7.1 with the arm that was included. The Grado Sonata 5mv MI cartridge cost roughly half what the turntable and arm cost. Perhaps an upgrade to the Grado Master, while affordable for the reason of a "re-tipping discount" available for existing Grado cartridge owners, may be money unwisely spent. I couldn't afford a whole new table right now, but the cartridge upgrade could be possible, and I've used the cartridge fairly regularly for about five years now and is sounding worn. Perhaps the entire system I've got wouldn't benefit from a cartridge upgrade and I should just get another Sonata? Maybe the Sonata is the best my current turntable can handle?
So, treading dangerously close to restarting what is surely an old and well-worn debate on high vs. low output; I probably just sound like I don't know what Shinola is, or what it's not. But my current question is in earnest: judging from the system I've got, is it worth it to buy a cartridge priced nearly what the turntable + arm cost?
Sincerely awaiting advice,
Nicky

A stylus has about a 2000 hour life span so you do the math! The lower output Grado has less windings and your preamp might not have enough gain.
You would have to find out the input sensitivity of your phono(.5mv or less)to make sure the lower output will work!
I use the 1.5 version of the Sonata which is called Sonata VPI!
I don't think your system would benefit with the more expensive Master!
For $400 the Needle Doctor will give you a new one with trade,they do not replace the stylus on them,they just replace the whole cartridge!
BTW: I am a big fan of Grado I have been using them for over 30 years!

By using a low output version, I suspect, you will hear very little if any difference in your system. I would check the capacitance and make sure its within the recommended bounds. Check your setup again and again to be sure it was installed correctly.. Call Grado for any hints.