I'm pretty sure I read somewhere that it wasn't to keep prices down, but because the motor wouldn't fit in the door....anyway, some part of the electric window wouldn't fit lol. But yeah if it really bothers you, there's some pretty decent aftermarket kits out there for them.
The shape of the door wouldn't allow the glass to recess far enough for it to constitute the cost. They can take some decent boost... On an aftermarket HG. The stock internals are cast, but I found no mention of forging....