The Coombe Women and Infants University Hospital has made a bid to build a new national children's hospital claiming that it offers the biggest and most flexible site.
It says it can be constructed at a cost of €358m, excluding the cost of fitting out the facility.
The hospital says its proposal does not require a maternity hospital to be built, saving around €100m.
This compares with the Mater plan of €650m, St James's plan at €510m and the €440m Phoenix Park Racecourse plan.
The Mater plan costings were recently revised down to €582m.
The Coombe hospital claims that it has a site of over 20 acres that is already zoned for a hospital and is already served by the Luas red line.
The report of an independent expert group, which is examining proposals and other issues, is due to go to the Health Minister in early June.
The Dolphin group has asked for more time recently due to the volume of proposals.
