I like the idea, but -1 on the 1 million exotic matter cost.
For most people 1 Mil EM is several months worth of mineral production, and they need that for legion missions.
I certainly wouldn't spend 500 purgers worth of EM on either.
Plus, i don't want to get into the whole when the RT screws you over, you get screwed again on the costs to take advantage of SM's or Ruins.
No offence intended at all to the OP, but everyone needs to get over this issue of trying to fix the lesser improvements that the Reality Transfuser can grant.
Small Moons are intended to be the booby prize of the RT and Ruins aren't bad at all. They still grant +20% arti, who cares about the +20% min/res. The only thing you lose with Ruins over Rings is the +1 arti from a Polaron Emitter and the double boost from an Orbital Stabilizer(limited anyway, so not really an issue).
So i guess my point is, you don't create an amazing & expensive perk to getting the booby prize from a Reality Transfuser, you are meant to just grin and bear it, otherwise you will just have people complaining that you need to add an equal counter-balance for LM or Ring planets.
If however, you are intent on bringing new ideas to the table, a good way to start is to take a look at artifacts already in play, to see what has been done before....
e.g.
Polaron Emitter:
If the planet has a Small Moon, Large Moons,
or Planetary Rings when this is built, this structure
gains +1 artifact and +1 mining.
Limit 1.
From that we can determine that the most Dan will do for your Small Moon worlds is grant an additional +1 arti/mining, and only once per planet.
