Well duh , it's not like they're using old parts of models from movies like SW

.
Every new CH character is built from scratch. Doesn't mean that they they use technology created for other movies on these movies as well.
ILM created sand effects for the Mummy movies and in Spider-man 3 they had go create start from scratch to create Sandman.
And they still paid a huge amount of $$$ for the VFX.
For Transformers they had to build complex robots with different parts fully fuctioning as a whole. Therein lies the difficulty of rendering the robots.
But like i said earlier , it's much easier to render METAL in CGI then something made of flesh.
Airplane rescue , the scene where he saves Metropolis from the various disasters.
Those to me were the scenes where you just needed a CG superman.
And you can go only so far with motion capture. WHich is a big help with the recent CG characters that ILM has done. Davey Jones is walking all the time. The iMocap stuff that ILM developed is a big help to get the body movements right. With Superman , you can only go so far with mocap because let's face nobody can fly
That's also one of the problems that you have with CG humans doing these kinds of feats. You need to get the bodymovement right otherwise it just looks like the characters don't have any weight and move too fast.
Okay how you you do the airplance rescue then ?
And before this resorts back to a "SR sucks thread" the point here it is much harder to get a CG human right then a big metal robot.
Even with today's realistic renders that ILM has produced , it still requires a huge amount of cash to create these VFX.
Also if you look at TF , the thing Michael Bay has done is shoot most things in camera. Afterwards the CG animations were inserted in the plates.
With movies like Superman or JLA you can't shoot everything in camera. Well you can if you hire a 1) jetfighter , 2) attack a filmcamera to it , 3) get a pilot who is able to withstand huge G-forces and 4) fly dangerously close in cities with speeds ranging from a few metres per second to supersonic speeds.
We all know that'll never happen. With a movie like Superman , you need to built CG cities as well , and all those things are expensive. Why do you think the Spiderman movies are so expensive. Do you honestly think that the bulk of the budget goes into the pockets of Raimi , Tobey , Franco & Dunst.
No , the complexity of the VFX determines just how much something is gonna cost.
Exactly .....sometimes. Not all the time