We are about ~300 years closer to Diocletian than Diocletian was to Ea-nasir. Too bad he didn't have access to Adam Smith, who could have told him that price fixing wouldn't work and might have pointed to Roman currency debasement as one of the major causes of inflation. Of course greed is always a factor I suppose.
Fair! Chronologically, at least, Diocletian's time is closer to us, though not technologically or population-wise. And by Diocletian's time, inflation was already out of control. If anything, the political stability that came with Diocletian's reforms actually helped bolster the economy, though it wouldn't last, as soon the center moved to Byzantium, leaving Rome (and Italy) to whither and die over the next century.