In our newer home, the basement was poured very unevenly. It cannot simply be filled as the uneveness is throughout a large area. (Imagine rolling hills!). What are the options for addressing this problem and what kind of costs are likely to be associated with each (e.g. hundreds or thousands of dollars)?

Are there alternatives to re-pouring concrete? Is it possible to level the floor another way (e.g. sub-floor)?

Thanks for any information anyone can provide!

Self-leveling concrete can be pour throughout the basement. Don't know the cost, it'll be thousands, not hundreds of G's. Get estimates for your area.
You can also put pressure treated 2x4 "sleepers" (2x on the flat, not edge), shim were needed, rigid foam between the 2x's, then 3/4" sub floor on top. This is assuming you have no water problems in your basement.
How new is your house? Can you get the builder involved? Having a basement floor that bad in a new home is unacceptable, IMO.

Armstrong, and maybe others, makes a cement like product called floor leveler. You could use a straight edge, and fill in the valleys with it. I am not sure it would have the guts as a floor surface itself. I have used it over plywood floors under seamless vinyl and it seems to do fine.

I back the idea of telling the builder to fix the poor workmanship if it isn't too late. I wonder what a terrazzo floor grinder would do?