You can actually rank up Goldsmith from rank 13 to 20 atm just making Brass Earrings. At rank 13 they're pretty tough to make but can give up to 900sp EACH (Which is completely nuts!), if it starts slowing down around rank 17 you can make Brass rings which give a little bit more SP than Brass earrings at that rank.

Not bad for something that only needs 2 brass nuggets, and the off-chance of making a +1 version helps compliment your own equipment if your battle class is around the same level