750watts

for a power supply....how many watts would one use during the course of flying in fsx?...does 750watts mean, that's the constant amount i'm paying for the time i use fsx? or could i be using and paying for only a fraction of that amount....now don't excuse my ignorance...send me hate letters...laugh at me, deride me, make me look like a fool, do not let me pass go and collect $200. go ahead...i'm ready for it 
