I can't figure it out. It's not any of the Prizms, because those say Prizm on the back in the upper right. All the others from this insert set this appears to be from, are Numbered much higher. My guess is that there is a missing checklist for a non-Prizm parallel set, but I don't know anything about this set to be sure. Have you checked COMC to see if any sets exist that we are missing, with cards Numbered /3?
I'm going to reevaluate how I collect after the new year. It's just getting way too expensive for the new stuff. Sometimes I just want to buy a pack, not a whole box or even blaster.