I'm just wondering:
we know that the Spurs haven't been very happy with Butler.
he showed up out of shape last year (one of the absolute no-nos when playing for Pop I would assume), they didn't like his progress, we heard stories of some of the veterans kicking his ass (Finley) or at least impatient rebuke him (Tim), he almost didn't play, instead of a not exactly outstanding season of Elson, he never seemed to be happy to be with this team and prfered to watch the dancers instead of listen to Pop. he was rumored to have been on the block last dead line.
his salary isn't huge, but it is what will likely lift the Spurs over the lux tax threshold.
and some argue about his upside, or his role on this roster. Butler is another Beno story, hopefully with the difference, that it doesn't take 3 seasons to learn that some players just arn't Spurs material, even if they are more talented than other players on the roster.
Butler will never play a significant role with this team. he might flourish somewhere else, but not in SA.
it's absolutly senseless to argue if he or Elson is more important for the team, because it's not a question of talent.