Hi Henry,
I'm not sure what you would consider cost effective, but I've used Arlene's Interiors on three occasions over the last 19 years and have been very happy with their products and service, from consultation to installation. They are in Burnaby on Dawson just east of Willingdon.

Hi Henry, I have used Designer Resource Centre (South Vancouver) or Westside Windows (Kerrisdale) . Good luck with your project!

Henry there is a place on Main/King Ed that does custom drapery. I cannot remember the name but heard it was affordable. Other names that have come up are budget blinds and Brite blinds. They sell more than blinds.

I can also recommend WindowWorks in Richmond.

I'm in Alberta but am thinking about using NikkiDesigns in Ladysmith for a few Roman shades in my new house. She's on Etsy, has more than 600 positive reviews, makes shades and curtains and more, and her prices to me seem "cost effective".

https://www.etsy.com/ca/listing/19253851/classic-custom-roman-shades-roman-shades?ref=shop_home_feat_2