As a tailor, I can make the Major Rune of the Mesmer (Rare) 2 different ways.
First I can make it with a crystal shard and cotton, and a level higher I can make it with a crystal core and silk. Both items have the same stats, yet the second one cost me 40 silver to discover, and I can only resell it for 20 silver since it can be made a cheaper way :/