How much do you think a forged piston option would cost?
Trick question, really. If you are talking strictly cost involved with the parts, and production....I wouldn't see it being more than $1500 - $2000.
I mean, you can get a stock Coyote engine right now for $6000 - or a Boss 302 engine for $10500. There are a lot more differences than forged pistons, when comparing the two.