Quality gear. These can be greens, rares, whatever. However, always think, "Who needs this?" Items that have stats like Stamina are typically useful to all players. Items with stats like Spirit are only useful to a subset. Items that combine two highly sought-after stats, like Stamina and Intelligence (which all casters need) will sell for more than items that combine two stats like Agility and Spirit (which practically no class needs).
A dungeon should take about half an hour to 45 minutes, that is reasonable. What did we do to Maw of Souls because it was by far the fastest dungeon to spam run for AP? Nerfed its yield. Same happened to dungeons. Except instead of nerfing the XP, they adjusted the clear speed to justify the experience a bit more. Is it perfect? Nah, a lot of dungeons aren't even that long with updates. At most a clear takes 5 mins more.