I'm sure if your builder is gonna go through the trouble to add the vents I wanted to the cowl hood everyone else is getting, he won't do it for free ( I wouldn't). At the least, he would need to make a separate mold for the vents and add them to the mold for my hood after he made the other nine. If it were me doing it, I would make a whole other mold for that hood to make it the best it could be. He might do that too, but either way, still not free
So to answer your question directly, it is the lack of ability to get the design wanted for the price I can readily pay. If I could still get the vents with the cowl hood for the same $700 everyone else is paying, I would still be in for sure. Unless you know something I don't...