it doesn't work. 

tested with basic ship and t1 research class "5% ship cost reduction on system", pumped both with same kinetic modules,  the industry cost is not affected anywhere (not in design screen, not in planet production screen), filled up the queue up to 55 of both of those ships, both types took the same amount of turns (150) to produce (same system obviously.)

not sure about other classes.

Checked also with the "price of beauty" perk to see if I can get any hints on how it should affect industry cost, and it increases the cost correctly (industry cost price is displayed and working properly) The special vaulter tech however has no effect. 

/edit1: just to be 100% clear I've also tested this type of ship in hangar and in orbit in case I didn't understand the mechanics correctly, still no effect.