Hm...
Standard Event Farm Unit: 50% chance on 55/7 map = 3 RC
vs.
150 DC Cyrus = 20 RC
If you can handle Crystal Keeper G, you can get 12-18 DC per run for 80/8 per run, averaging to 10 runs per Cyrus, for 800/80
Event unit would need 7 copies to tie (actually, barely beat) 1 Cyrus, so 7 x 2 (50% chance) x 55/7 = 770/98
Due to Stamina being in shorter supply than Charisma (at level 200, you have like 420 Charisma but only 18 Stamina), Cyrus would be cheaper for SC usage. Of course, we're assuming non-whale so you'd basically want to combine the two when farm events come around, going for as many event unit copies on every day but Thursday. Since not every event is farm unit, Cyrus is more reliable, per se, but you obviously get many more runs of the event map in purely due to Cyrus' DC being available only one day a week.