I am making a suggestion in regards to adding an additional search refinement.
My suggestion is to make a location where you can select your profession and thereby being able to search for all items that, for example, an engineer can use.
I think that this would increase the purchasing/selling experience and also increase the in game economy as it will allow more people to see the items that they may be interested in instead of searching by name, level and/or rarity.
Just puttin’ it out there,
Tom