In a previous correspondence with Mrs. Goulet, she said that Iroshizuku won't let the Goulets go lower than their current price. I asked back when Yama-Budo was in the Ink Drop, but it didn't go on sale that month for Ink Drop members. She apologized (which wasn't necessary ) and explained that Iroshizuku wouldn't allow them to sell below that. I don't know if they would actually drop them or not....
The Iroshizuku price is set by Pilot USA. According to Art Browns, where you could have bought any Sailor ink before about 6pm today, PILOT USA complained when an on-line ink company began to import Iroshizuku inks, by-passing Pilot USA, and sold Iroshi at about $20 a bottle. Pilot said, approximately: "The MSRP is $35 per bottle. Retailers can discount 20%. Any retailer who discounts more than 20% will have no Pilot products...none at all".
Pilot's intention was and is to have all imports to the US through their licensed distributor. WalMart might have more negotiating power, but the business principle is that a company won't want to be your US distributor if retailers can find another channel to get your product.
On the Sailor issue? I don't know. I just happened through this sub-area after lamenting the closing of Art Browns. A shop where I could walk in and pick up nearly any ink, and where the staff knew my preferences and had their own opinions: "XX Blue? That's not blue...it's a purple that only THINKS it's blue".