The table pictured below is from the summary of the chapter on openings in Dr. Emanuel Lasker's 'Manual of Chess'.
To fix the exchange value of the Pawns and pieces and the move, in order to decide whether we may sacrifice a Pawn for so many moves gained in development and similar questions, the table will be found to be a fairly accurate guide.
These are, of course only estimates based on experience. The numbers given are only approximate. But even though the position is complicated, they can still be of service in helping to determine whether one may venture upon sacrificing a piece for two Pawns, and in elucidating similar thorny problems.
Since chess960 is only an expansion of the start position used in traditional chess, can we consider how Lasker's values -- or any other system that tries to weigh opening variations objectively -- apply to the 959 other start positions? The main factors are the value of time, the value of center vs. side Pawns, and the value of specific pieces.
Lasker's complete chapter summary and table can be found on books.google.com: Lasker's Manual of Chess By Emanuel Lasker (p.107).