Return items back to vendor and buying confirmation.
I’ve been hit by this too, albeit for only 420 karma. I meant to preview a piece of armor, and a couple misclicks later it was in my inventory and I was out 420 karma. I weep for you my friend. Option 2 would be easy to implement.
Perhaps they could do the same for, say, cultural armor dealers. The system doesn’t need to be item-specific, but merchant specific. Certain key purchases (that don’t happen frequently) could certainly use a confirmation.
This gets my vote. A couple of days ago I lost ~20K karma and 50 dungeon tokens to useless crap while just browsing for potential skins. In my case it wasn’t ANet’s fault (my mouse was flaky and was turning single clicks into double clicks everywhere, not just in-game; has since been fixed), but some kind of confirmation or sell-back would have been very nice to have.
Seconded.
I spent 21k karma at the vendor in LA at the end of the pirate jumping puzzle for an item I couldn’t use when I clicked on one I did want, but for some reason that click didn’t take. The cutlass I wanted even looked highlighted, but I got a short bow instead.