Liberal Eddie Joyce has been hounding the government in the House of Assembly, looking for a commitment on timelines for the project.
The province has said an engineering company was hired in October to review and refine the master plan which it says should be released early in the new year.
In response to questions from Joyce on Thursday Dunderdale released the new estimate and said the required planning is being done.
The hospital was initially estimated to come in at a cost of $750-million.
The project was first announced in 2009 with a construction completion date of 2016.