In my case, I sent out architectural shop-drawings of my designated audio outer building and long with all electronics placements as well as the sweet listening position. I also attached photos captured of the current setup, each view of the four walls.
I received two quotations from two different designers. One was $17.5k and the others was $14.5k. I only order portion of one design and hoping to diy the rest to save funds. That particular designer was fine with my decision. So I spent $5.5k for 2 corners at front wall, 4 fulltrap. 2 max trap for rear side walls, and 4 flexifusers for rear wall. For ceiling and sidewalk first point of reflections I plan using the existing..... for ceiling, I plan to diy some big panels to hang up at front and on top of listening position.
That is my plan in a nutshells...., your constructive input is welcomed.