Time and time again you've shown that you don't even know what the hell that cost model is, which yet again is your angle to denounce the race because you think as you've seemed to from the start of joining this topic that only one group can obtain such numbers. IMSA isn't the only one and to be frank you haven't looked at the other things like LMP3 and more uniform rules that allow for easier access or or straight forward LMP2 projects across the board.
The only model that is obscene in cost is P1 and then GTE since it is essentially a development class (the difference between it and GT3). Also who cares who submits what, you submit on the onset that someone may drop out and you get picked up by the ACO to join. However the spots are usually filled by the invitation to actually go to the race. I'm sure someone like
@Furinkazen can better explain this too you in what you're missing. But the ACO hasn't had issues to the extent you seem to be on about. And the race still ends up being the biggest race of the year internationally.