The price is high considering any company wanting to make these, do so off a nice door to begin with.
The OEM Alloy door is roughly $100 at the dealer. From there, you do the overlay on the door piece with the CF (time/material), then add other overhead expenses, shipping, etc. So I can see where the price is 175-200. My estimate to make one of these for the 3G is $195, which is VERY close to where you found your price from.
i paid $180 for mine, i sent my alloy one to a guy and had him lay c/f on the center part wetsand then buff, it turned out great, and i have never seen another one around like it. but its the only thing on my car thats c/f now. so im thinking of selling it. i painted my badly faded and cracked c/f hood and all of my black accents are painted black not c/f..