Should be less than $1 per spoke plus wheel building costs.

You'll end up with bullet proof wheels that'll last ages. I've ridden over a 50x50 (2 x 2 in the old measurements) post lying across the road in the dark going about 25kmh on my training wheelset (DT & Mavic CXP22 rims) and not busted or bent anything - I just got a hell of a surprise at going airborne suddenly.