I'm not sure why?
the .364 "9mm mak" bullets are pretty easily found these days...maybe not as cheap, but by no means hard to find anymore. Casting molds are available as well.
Standard 9mm brass can be used in reloading, however...which will save you a pretty penny.
A few things to look for.
The cases WILL need trimming, which (depending on your equipment) can be time consuming. Each case needs to be trimmed approx 1mm.
Beyond that, the 9mm makarov bullets (again, larger diameter) will cause the brass to swell to an extent an initial loading. After being fired once in the Makarov chamber (fire forming) you'll be good to go until the brass is worn out.
It is important that you MARK THE BRASS in some way....
1. so you can keep track of what has/has not been trimmed--and what belongs to what gun
2. but also so fellow shooters at the range that may accidentally collect your brass can realize something is different from their standard 9mm stuff.
For $115 you got a Sweet deal! These firearms are VERY accurate thanks to their fixed barrels. If you treasure the accuracy and the firearm itself, don't try shooting .380/9mm bullets through it.
ENJOY!