In most cases the season pass is less money than every piece of dlc, even then if it is the same price only buying say 4/6 dlc would be cheaper for the consumer. You can take a look at any game on steam that offers a season pass, it vs all the dlc for it. From my experience with season passes it is 'slightly' cheaper to buy it than if all the dlc by itself. Buying 4 characters would be cheaper than buying the season pass.
I said only buying the characters alone would be cheaper. Speculation? or do you have proof buying all the dlc separate will be cheaper? I can't see them doing this as they'd lose money.