Hello .... my 2-cents worth:
HOw much it costs really depends on what material you use.
I launched into a reserach on this some months back .... the Malaysian curtain shops is not THAT cheap. The material used is not so good quality, and all that hassle of travelling to & fro the causeway will only cost you more at the end of the day. Not to mention the phone calls ....
On the other hand, i went to some local curtain shops in Tanjong Katong Complex. The price they charge is reasonable for the quality. In fact, the same cloth i chose from the Malaysian curtain shop was cheaper here!
Ultimately i signed up with a local curtain shop. I'm doing day and night curtains for the living and dining rooms, day and block-out curtains for 3 bedrooms + 1 roman blind for the master bedroom. All in $1500.
I dare not post the name of the shop that i've signed up with becoz they haven't come to install the curtains yet. You know how the sales talk is like .... everything can, but when it really comes down to doing it, they say cannot.
Anyway, i'll keep you posted on the outcome of my curtain installation soon.
Good luck w your search !