In the starter town you can buy a lvl 10 necklace from the NPC accesory dealer for 32 lant.
Cost to reduce it at item reduction blacksmith is 11 lant.
You always get a crystal, it never fails.
So the Crystal has cost you 43 lant and a little legwork.
Now 50 Ordinary crystals are currently selling for 20,000 lant in the auction house,
that works out at 400 lant each, making you a profit of 357 lant for each necklace you buy.
Of course if you buy the Item reduction 30 day tool from the Mall then you dont need to do the legwork
and it wont cost the 11 lant to reduce it.