I think that regardless of budgetary concerns, the only way the Silmarillon could be adapted into film and not be a load of tedious, incoherent nonsense would be as a series of short vignettes--animation would be favourite--that tell (very) abridged versions of some of the key tales of Middle Earth. Something along the lines of The Animatrix
or Gotham Knights
with a bunch of smaller shorts and one much longer one telling the broad strokes of the first two ages right up until the Last Alliance. A mishmash of different styles to suit the individual tales. I would make a nice companion piece to The Hobbit
prior to release but it probably too late now to make that deadline. For one thing, I have no idea if anyone owns the rights to The Silmarillon
or if the Tolkien estate would be willing to sell them in any case.