And for the investor, what happens if you put all this money in only to have the players cave to the owner the day before the 1st game?
This is why they would never find an investor willing to put up what is necessary. No one will want to sink a ton of money into something like that, just to be used as leverage.
The only chance they would have would be to go all in, and have guys commit to the league NBA or no...and that will be hard to do for anyone still with an NBA contract.
Players can keep their heads above water by playing these glorified pickup games, but to put together a legit league, it is going to take a lot of money, and a lot of organization, and especially a lot of commitment to make it more than simply a leverage move, but a legitimate attempt to compete with the NBA.