Custom Board Design costs

I searched the forum and didn't see this posted yet. I just wanted to get an estimate of how much more expensive it is to get a custom board vs a stock. I am specifically interested in a spitfire. I had a 6'2 spit but sold it as I grew out of it. I am interested in a 5'11 spitfire with the width and thickness of the 6'0 (20.5 x 2.5) or the dimensions of the 6'2 (20.8x 2.63) spitfire. I haven't decided that part yet. I would prefer the FST (more ding resistant than Rapid Fire?) I'm just looking for an estimate if you can't give a specific price. Currency = USD.

Thanks
Justin

Side note: I thought about a 5'10 potatonator but I already own a sweet potato type board (5'5 x 22x 2 3/4) and want something more like the spitfire.

it's $75 more than a stock board

What about for Aussies ?

Hmm good question. The same I think. It should say within the CBD section of the website.