Everything costs more that it did in the 70's for one.
And, that synopsis sounds fishy.
We're not talking AVATAR here. $250 million is an awful lot for just about any film, though it's not so bad if it's actually being spread across two movies.
The synopsis matches up with the script I read earlier this summer, although their summation was a little snarkier than I would have liked. Also, the few public comments that Ridley's made since then also match up with it. And finally, I doubt Fox would have had it pulled if it weren't the real deal.
Of course, we know it's gone through some (possibly significant) rewriting, and I have no idea what changes were made since Damon Lindelof came aboard.