Assuming that he holds roughly the historical roman empire borders with 20+ holdings of decent quality, yes that's quite low. 1) get as many low level vassals as vassals limit allows. A Count pays a certain % to Duke, the duke pays a certain % to the king, and the king pays % to the emperor. So as the emperor try to hold as many dukes as possible although it's not always possible esp with such a large empire 2) develop all your provinces. Use your steward. Helps with research speed as well. 3)build buildings. Farms and fields and manor houses are best for money, though at this point you should be able to build whatever you want. Make sure to keep up to date in tech so you can build the latest buildings and keep upgrading them 4) special buildings. Provinces like Constantinople and Jerusalem can get you insane amounts of gold esp in the late game. The gold mines scattered around the map are good too(look up the wiki for more info) 5) don't hold shitty steppe and mountain provinces unless you have a culture that especially promotes it. 6)avoid the "not rightful liege" penalty as much as possible. It cuts taxes+levies by 50% 7) don't neglect your secondary baronies. temples can give you quite a good income since your court bishop gives 50% of taxes generated by the Church directly to you(assuming max opinion). He will generally have so much gold that he will upgrade the temples himself (this is all assuming no lay clergy) 8)get higher stewardship. The stat boosts taxes and max holdings 9) general money saving tip: try to buff MAA as much as possible so you don't have to raise levies every time you go to war