one of our members here does curtains
her nick is http://www.mummysg.com/forums/members/sunshine07/, you can send her a PM to ask her on the pricing and details.
$$ comes with quality, so if you r looking for custom made curtains there has to be some cost associated with labour and workmanship which cannot be compared to those ready made ones.
If you r really really on tight budget, suggest you buy ready made curtains, a pair only costs $50 to $60, Giant, NTUC at AMK Hub and SPOTLIGHT all have nicely designed ones.
and you need drill up the Curtain rods and such. More like a DIY.