As others have said, no thanks. We already have 5-6 backcourt players under contract next year. Furthermore, Evan Turner has a cap hold of $4.4 million. I'd much rather use the $4-5 million of cap space you suggest for Augustin and try to instead allocate it to Turner in the form of the Early Bird exception.
Maybe if one of Rozier or Smart were traded, and we didn't pick up another PG in the draft with one of our 8 picks, and Turner walked -- maybe then I would be fine with offering him the room exception of $2.9 million. But he should be like plan Q for this team.