I imagine that the Allomantic device market would be rather niche; maybe Ranette-style home improvement projects for Coinshots and Lurchers who want to exploit their abilities to the fullest in everyday life, specialised coinshot ammo, flavoured metal shots, fashionable metalminds (or imitation metalminds), retreats for storing as much as you wish (health, speed, strength, senses), lens collections and hearing aids for windwhisperers that want to maintain normal senses while storing, magnetised powder you toss in the air to find Iron Feruchemists, Thug brand home gyms designed to require more strength than any normal man, metal stars for use by Coinshots to tag someone. Also, plastics, ceramics, and glasses as alternatives to metal in high-security situations - perhaps your bank vault has a ceramic lock mechanism so a talented Lurchers can't see the positions of the tumblers.