This posting would be too late for original posting. But want to share my experience and research as I had same issue and fixed it.
The symptom above is due to lack of vacuum at brake booster but root cause of brake booster issue can be (1) connection hose issue , (2) vacuum pump issue, (3) booster itself issue. My case was vacuum pump issue which caused leak engine oil into hose. It caused oil contamination into connection hose and booster. Oil contamination in booster causing brake failure which is very dangerous. You can check Youtube how to check booster issue. Anyhow, when booster issue comes, mechanic would recommend to replace Booster, connection hose, Vacuum pump.
Total part cost (in Jan 2017) at Eng Soon for Booster (OEM): 350 SGD, connection hose: 80 SGD, Vacuum pump: 200 SGD. Taxi cost to come & back from Eng Soon to my workshop: 40 SGD.
Replacement labor cost will be various per workshop. Honestly and shamefully I paid too much on labor which is 430 SGD for 5 hours work. Also I paid brake fluid flushing at 100 SGD.
Total cost was 1200 SGD for three parts replacement.
What I got quote from a workshop (at bukit batok) was 1180 SGD for booster and connection pipe only. Booster cost in their quote was 870 SGD!!!! more than double! So I asked them to provide just labor for replacement then WS raised the labor cost to 430 SGD which I had to agree as my car was already dismantled for diagnosis.
