When should fixed and variable monthly budgeted expenses first be planned?

Fixed expense refer to the cost that does not fluctuate no matter how much you produce or sell,

Variable expense refer to the cost that fluctuate according to how much you produce or sell.

They both should be planned and budgeted before the operational process, Ideally before the new operational period began ( every 1 year)

Complementary goods. they go together, thats why one price increase and the others demand increases

It is edm or dance/electronic music.