To further build on that idea, why not have weapon crafters too?
It would further put a stem on the brazen prizes that people can charge for new greens (remember 300K for a RZRSTONE? or 200K + 10 ectos for a rago's flame staff?) as well as control the rate of inflation.
However this idea is not meant to undermine the luxury status of some weapons at all, and as such crafted weapons should probably have the following down sides:
1) It is customized upon crafting, so it can't be sold (perfect gold sink!)
2) It can't be further modded and salvaged nor dyed
3) Crafted weapons will have generic names, so instead of "I'm welding a rare furious crystaline sword of fortitude" it will just be a "I'm welding a furious crafted sword of fortitude" although it have the same skin.
4) Price mods and skins accordingly, basically the NPC should just keep jacking up the pricing for a model or mod to as high as the market will bear (think Apple computers

5) To further enchance the "RP" nature of the game, along with gold costs, once you have designed your weapon, a random concoction of monster body parts/collector's item will be given to you in the form of a quest, which you will then need to complete before the crafter will even tend to your patronage

6) These weapons will have a pathetic merchant value of 35g, the same as any old green weapon, even though it might cost 100,000g to craft it.
What it'd serve to do?
For starters, people no longer will need to "grind" as hard to get that perfect crystaline sword they always wanted so they can "look cool".
However, bear in mind that the intention is not so much to make supposedly rare models worthless and commonplace, but to actually:
1) eliminate the need for people to turn to skins and model to differentiate themselves, they are free to build their character to their exact "specifications" to conform with their vision of how their character should be
2) as it is a crafted sword (and the user knows it), it is no longer like he can craft certain sword and flaunt it to everyone else, which we all know is so damned annoying

3) Did I say these swords are perfect gold sinks? Even at 100K, 20 ectos, 10 rubies, and a few various odds and ends, each crafted weapon is essentially gold and materials that is absolutely purged from the economy. It is not salvagable, it only sells for 35g, it is customised and have no more luxury status than a blue collector's item.
The rich can of course still retain their own unique position in society by being able to weld weapons that are infinitely customisable, still as rare as ever, without any chance of having their value challenged by the crafter.
How you find this idea? With some tweaks and further additions it might turn out to be a great idea!