...save until you have enough money to win the b3 IMO...
A lofty and honorable goal indeed. And not relevant to any mid- level or lower-level team.
THere is nothing lost by building seats.
This completely false assertion can be repeated only by someone with no clue of what
opportunity cost is. This may help:
"DEFINITION of 'Opportunity Cost'
1. The cost of an alternative that must be forgone in order to pursue a certain action. Put another way, the benefits you could have received by taking an alternative action."
You may google "opportunity cost" if you still don't understand how it applies to the money lost building empty seats versus how it could have been put to an alternative action, for example buying players or a better trainer. Only when there is
absolutely nothing else to do with your money is the opportunity cost zero, although I would suppose that even then some would argue that options lost is an opportunity cost, too.