HDB has done most of the work... So it takes the guess work out... Life is about relativity...
http://www101.hdb.gov.sg/hdbvsf/eampu03p.nsf/0/12MARSBFM_page/$file/main.htm
This shows you the pricing positioning in each hdb estate and will form the basis of relativity of the condo in each estate....
So, as u can see, hdb priced queenstown area more than bishan... So technically, if comparing apple to apple, echelon should be higher than sky habitat...
You need to dwell into each area more(like is the hdb near mrt, etc....) to get a better pics... I am just doing it as a ball park...
Hope u all can learn something about comparison... Just like looking at PE ratio of stocks...
Cheers