From SAS perspective not enough value for a first round pick.
From PHI they don't do it, because it leaves them with potentially 5 guys (3, 16, 19, 23 and Saric) asking for 1st round contracts guaranteed contracts next year, out of a 15 man roster! Not to mention the young kids they already have! They don't have room.
I would suggest something the other way
SAS's 2016 first (lottery protected) to PHI
for
2015 16th pick (MIA via PHI).
They get to delay a pick by a year, and hope we fall off (which could happen anytime if Duncan and Gino retire); we get a mid first pick in a deep draft, which we can hopefully pull a Kawhi with...