Geez the Seleucids are good if you can hang on and get through those first few years of strife - I'm rolling in dinarii with all my high-trading coastal cities like Antioch, Sidon, Tarsus and Alexandria, plus lots of trade coming from the east as well - and once you've got stable borders (ie eliminated Egypt, Pontus, Greece, Parthia, Armenia and Macedon) you can sit back and rake in the cash, and keep building staggeringly huge armies of elephants, scythed chariots, pikemen, peltasts and cataphracts. I've got my eye on Numidia and Scythia next, then I'm going after the Germans and the Gauls.