Obviously your corps arent making profits. Are they still upgrading? while they are they are unlikely to make much. Are they hiring at 100%, is production (tied to welfare) at 100 or over? Are you selling all your product every month?
There's lots to consider, base line is are they making at least a couple of hundred million each month, minimum.
As for profitable CEO corps (stand alone profit) a very rough guide would say salaries of 250 - 300, supplies of 160 - 170, best price buy and sell. Always upgrade unless you have a good grip on supplying your self with your own goods. Use the world market or a common market for now.
And remember, your state corps or private corps will pay you every month, when you IPO a corp you get a one off large payment but for that you scarifice a part of or all of that income.