It really wouldn't stop people from farming to NPC items. That's an individual decision and opening more selling options increases NPC sellable items. People can still NPC WSS if they have no need for it. Which honestly unless you are a verteran with an Alchemist Character or know an alchemist character you are going to either Sell it to an NPC or sell it to another player.
Considering I've had shops opened and nothing was bought from them within a three day period I'd sell WSS to an NPC because they are useless to me and I want more Zeny. There are better things to sell, but I get a good amount and they rot in my bank for a long time and I get tired of seeing them there.
Again, it serves less benefit to new players or newb WoE players as Vets get more, use less and benefit from it greatly. It isn't really a Zeny Sink as it increases Zeny flow into the market. Some it sinks Zeny into but they aren't paying as much per due to increased number in the market and those that only hunt to sell are making less per item while increasing their own zeny to be used in sinks later.
As a Zeny sink this is fairly poor. As an attempt to increase others to come into the WoE play, it completely fails as Vets get better support with this. If you try to look at it for the bragging rights of being ranked, Rankers already can increase their rank if they wanted to. This would increase their chances of moving up but not by a whole lot as there isn't any real incentive to rank up.
Only reason to add WSS is because you are lazy and don't want to go hunt them from their normal monsters which is already fairly easy.
