While I was talking to Smitty I was reminded of some stuff and updated the Champions Character Creation Cheatsheet.
He reminded me of the formulas for computing Active Cost (the cost after Advantages), Real Cost (the cost after Limitations), which are ultimately the formulas for how you compute the cost of any power.
It used to be that you lived and died by these calculations. Nobody could make a character without knowing them and they would have been one of the first things I added to the CCCC. What changed? Hero Designer. The computer program does all this stuff for you, so pretty soon you don't think about it anymore.