I got my sewing chair at a quilt shop, It is OK, but the chair I got for my long arm room which I used to use when I had my smaller mid-arm on a frame, I got at an office supply store. It was used, but I still paid $100 for it. It was made by Herman-miller. It is very adjustable and very comfortable. I would sit on it and roll along the concrete basement floor as I was doing pantograms as I was having foot problems. If I needed a new chair, I would again check out used chairs at an office supply store as it is the most sturdy and comfortable chair I have. I also got a computer chair at an office supply store, but again, it doesn't not compare to that used one.
Oh, and the reason, that used chair was for sale was that a large company in town changed their color scheme and did away with the dusty rose ones.