Your fear is not baseless. That must be experience of past or some close friend or relative of you. The simple calculation behind this is many designers charge on percentage basis. So whenever you select anything expensive, the fees goes up for the same job. But with ADD you can rest assure as basis of our fees is your carpet area and not the percentage. As long as carpet area is fixed and scope of the work is unaltered, so are our fees. So with ADD you are free to select the things you want.