Can't remember the cost but I had concertina blinds fitted at the house by a guy with a curtain shop on Naklua Rd, made of bamboo. Came down Sawangfa, left at Naklua-Pattaya Rd and on the right after 100m.
https://maps.app.goo.gl/4kSL2tbVcAM2SofN8
There was a shop also on Sawangfa.
Did you try Homepro, maybe do roller blinds?
They can also be bought off Lazada.