Khome, this is a little tricky.
There are quite a few strategies not everyone understands them and they are heavily dependant on circumstance.
Salary level effects productivity, in turn productivity effects revenues (profits too sure, but profits can go up or down) revenues seem to have a larger bearing on CRU'd. What I'm really trying to say is not only are your people more inclined to pay your countries expenses, but also higher salaries will lead to a much larger benefit then lower salaries from CEO's. If they aren't willing to pay 300, you don't need them, I'm sure there are plenty of other CEO's that would be happy to build corps. With that said you can even do 299 if you wanted but more realically 250-275-300. If you are struggling too get them then it is almost assuredly a welfare index issue. Remember you want this to be mutually beneficial, and not result in them taking advantage of you.