The Florida Symphony, which is hoping to add a full corporate headquarters to St. Petersburg’s Mahaffey Theater, hit a roadblock this week when the initial construction estimate came in $1 million over what had been budgeted. “Under current plans, the 10,000-square-foot headquarters would be housed in a new wing at the northeast corner of the Mahaffey, which was recently renovated. It is to include offices, a music library and space to store instruments.”