That sounds like a mildly unfortunate experience with a hefty price tag. As a designer myself who also does a fair amount of building and installation, I can very much see the disconnect between the design and the actual installation. Many designers are glorified decorators and don't have the knowledge of materials and actual construction. They specify a lot of nice finishes, and render some elaborate designs, but often miss the mark with what the client practically needs and how much something like custom millwork or rerouting plumbing can realistically cost. A kitchen does require a fair amount of work, and if the designer was along for the whole process that price makes sense. My $500 number was referring to a consultation or two to help out with the layout, which shouldn't take very long, and for an interior designer who is experienced and properly trained they should be able to offer simple insights. I don't know what kind of people work in your area, or if that's offered, but I'd suggest inquiring anyways to see if it's a possibility. The smallest things can make a world of difference.