We had a wonderful installer put OKNA 800s into our whole house last fall. He quoted $1800 for a garden window, installed, in our kitchen reno, which is fine. Our contractor came to take a look at the project and I decided to increase the width of the window by 6" (ditch the moldings to get a bigger window that is more centered above our sink base). He quoted $1250ish for a Certainteed window + "several hundred" of labor to redo the framing around the edge. I'm guessing the 6" bigger (42"w) will be a bit more from OKNA. I love the OKNA quality for our house, and am finding only lukewarm thoughts on Certainteed, but are there additional considerations for a garden window that I should look into?

It will certainly be easier to have my contractor do the demo and install as he does the rest of the work, but my gut says I should just get my OKNA guy to come and deal with the slight difficulty of scheduling two guys.