I'm having the same problem. When I entered
/Applications/Sage-4.7.2-OSX-64bit-10.6.app/Contents/Resources/sage/sage -c "print os.getenv('PATH')"
I get
'import site' failed; use -v for traceback
Traceback (most recent call last):
File "/Applications/Sage-4.7.2-OSX-64bit-10.6.app/Contents/Resources/sage/local/bin/sage-location", line 3, in <module>
import os, sys
ImportError: No module named os