Stepping in several shops that make curtains and making an inquiry based on measurements and asking for low cost material, they sit down with a calculator for 5 minutes and then quote in the 10,000 baht range for just one window covering . This is such a striking price difference to going to Big C and buying premade for just 700 baht which I point out to them to no avail. Due to a L shape, I think I am going to need a custom solution and also want black out. Any suggestions on where one might find a reasonable price on curtains?

My experience in buying custom drapery in Chiang Mai may be of some background help.

I spent 2500 Baht a 1.5 meter wide panel for each of my sliding glass door panels pre-made with hardware at HomePro. The same drapery at a custom shop was approximately the same, ie 3000K Baht per 1.5x2.5 meter panel with hardware.

My conclusion is that the hardware for your drapery will be the overiding cost. My "roman shade style" type hardware cost 1800 Baht a piece for a 1.5 meter wide window, the fabric for the same size window/door was for a 2.5 meter high opening and was only 1200 Baht.

I did get the lower end mostly solid color fabric without blackout backing. So expect to pay more for the fabric and it may equal the hardware in cost before your finished. Of course, fabrics can get very expensive, so it will be up to you to control the price by watching the quality of fabric you choose. The type of hardware you choose will likewise affect your cost.

Labor costs are relatively low, so fabrication costs and installations costs are nominal and are usually not quoted separately.

I would check HomePro. They can do custom curtains. Anyway I bought my curtains at The Mall Bangkapi (70% discount at the time for Pasaya curtains), and the curtain bar at HomePro. I had my handyman drill in the bar.