It depends on the size and time. Lets say one were to scratch-build an OF about the size of an MG Gundam... Roughly 8-9 inches tall and in fixed-pose since a posable kit is more difficult. If it's a one-off and not meant for resin-casting then the cost for one would be more since no profit would be made on the multiple castings. Even with castings, the cost would be high due to materials costs, just divided between casts.
So one needs to figure out how many hours the kit would take to sculpt. This depends on the modeler. I'm guessing quite a while though. 80-120 hours at least. So lets pay our modeler a rate of $7/hour. This means that for labor alone you'd be paying $560-$840 at least. Factor in cost of materials and that could add another $100-200 in putties, tools, plastic, glue, resin and rubber for dup parts etc...
If it's a resin kit where multiples will be made then you need to pay for the mold rubber to make the molds. These are only good for so many casts and mold rubber isn't cheap. You'd also need to buy the resin for each kit and buy packaging.
So basically... it's not cheap and my estimates are on the low end. :wink:
