I think it would be helpful to have a "back to search" link/button after you purchase an item from an NPC shop, like there is when you buy an item from user shops. I rarely shop from NPC shops directly, and am always directed there by the shop search.
I'd like this for all shops (restocking, non-restocking, holiday) along with a Add to Wardrobe button for all shops (I'm including Holiday-themed shops in this, too)

Hells to the no. D:
I routinely restock from NPC shops and this would drive me absolutely bonkers to see after Every. Single. Purchase. Not to mention the fact that the button would probably be way too HUGE and VERY BLUE and surrounded by too much white space.
The other time I'm using NPC stores and shop search is when I'm questing, and I wouldn't want a button directing me to shop search when all I want to do is go back to the quest itself.
I feel the back button is fine.
I don't think it's necessary. Often I'll open whatever I'm buying in a new window from the shop search anyway, but also you can use the back arrow/alt left arrow/right click back to go straight back to the search results.
There would have to be a way to differentiate between users buying the item from the shop interface itself, versus buying from the search results. Because it should not be showing if you're buying an item from actually being in the shop.
Ick no thank you. Use your right click to open in new tab or window. This way your ss will have remained as it was.
My mouse has a back button so it's not TOO big an issue, but I wouldn't complain if it happened. For consistency's sake if nothing else, since the user shops have that function.
That seems a bit unnecessary and maybe even impossible with the search purchase vs normal purchase.
I think a better idea for this would be enabling the hover on the purchased page, as it would only load one item and it would also just be a click away.
If going to the back button of your browser annoys you too much, I'd definitely suggest you get a mouse that has extra buttons for that. I got one myself for the same reason and it's pretty practical.