Not Elwood but inner city
Not a direct comparison, but not all value adding exercise actually adds value to the property. A recent experience albeit in Sth Melbourne and a house (couple of k's away) was purchased in February 2005 for $582.5k. Block of land (with existing dwelling) was 7 x 42 which is great size for the area, rear access too. Up for sale again just recently, this time with plans for extension and a second storey, lap pool, etc, the full catastrophe. Sold for $601.5k in May 2006.
There are far more 2br apartments (older style) in Elwood than 7 x 42 blocks of land in inner Melb suburbs. Ultimately recent sales of comparable unrenovated and renovated 2 br apartments will dictate the size of the opportunity.