Are you joking? The SLS is a pretty major step backward for American spaceflight. If we continue flying the SLS, and make all the launches we plan (spoiler alert, that isn't going to happen) then the cost per launch could be as low as $2 billion. But more likely we will end the SLS program when it proves to be a never ending money sink, and with so much money put into development, we'll end up with a per launch cost upwards of $5 billion. Meanwhile, for that price it can only manage to get 95 tons to low Earth orbit.
Compare this to the Saturn V, which could lift more and cost much less, even when adjusted for inflation. The Saturn V cost $185 million, or $1.23 billion adjusting for inflation. And it could put 141 tons into low Earth orbit.
To sum up, this new rocket is much less capable and much more expensive than what we were doing 55 years ago.
You could of course also compare this to what spaceX is doing... Their aim is to make a rocket of similar payload capability 100-150t, but with a per launch cost of about $100 million via reusability. That's an order of magnitude of improvement, that's huge.