quote from my ID for windows ( white powder/ green tint) is about 3k for a 5-room flat. and my WIW for 12ft is 2k ( without doors) . problem is I'm converting a whole room for my WIW and w/o doors will be very messy and dusty. just wondering if you guys outsource it out to other contractors and if you have any recommendations/ feedback on this. My ID is quite insistent that I do it thru them. also some misc questions if you guys can help: 1. quotation does not include re-wiring for house ( almost 30yr old hse) and I'm very sure it will pop out as 'hidden cost' how much should I budget aside? another ID quoted me about 4k 2. what other hidden costs have you guys encountered so far. 3. what are some of the reasons/ excuses you guys use to push the price further? my budget was about 30k,but all came back with 45-48k quotes, even after taking away all the unnecessary, it's still about 38k note: Flooring needed only for kitchen + 2 toilets + balcony. the rest are original marble