Good thread, I would like to hear it too.
In my case was because I wanted to update the photos of the Guild Wiki of each weapon page, there are many that are in very very poor quality and resolution.
I started buying weapons only because the skin, for 1-3k, regardless the Q or rarity, to replace the old pictures with new ones with max. settings and the option of Anti-Aliasing 8X activated. Then at the beach of Great Temple of Balthazar (and using the GW Toolbox "/camera unlock" command) I took the photos with better light, better angles, zoom, etc, with the character facing the sun and inside the seashore to have the background in blue or white depending the color of the weapon (some fits better with the color of the water or the color of the sky/clouds, for example for the Ancient Daggers I used the sky background, because the blade is grey). Then in Photoshop I apply a Color Balance +10 in Blue to have the original color of the environment regardless the sunlight (in this case, at GToB). And then the Wiki.
From that moment, when I saw that I already had a long collection, I started collecting weapons for my daily use and personal storage, golds, greens, Q9's, etc. I checked all the galleries of weapons of the Guild Wiki to write a list of everything I wanted, and I started buying everything with patience. Some were farmed, others were bought and others were given to me for free, it has been a mix.
And the last set of weapons to finish everything was the Ancient ones, that I acquired yesterday finally. Since kid I have loved Egypt and the mysteries of ancient civilizations thanks to Stargate (1994) and Stargate SG-1 (1997), so every environment containing dust, sand, pyramids, ruins, deserts, wastelands, dry plants, temples, stones, grey skies, ruined buildings/constructions, archaic legends, old myths or stories, etc, etc, etc, they make me immerse myself in the history of the place and I want to know everything of it (that's the reason of Nightfall being my favorite game, regarding the wastelands and African landscapes). I also love the Elona Desert from Prophecies, it's a pity that ArenaNet never finished the Lonely Vigil or Glint Statues missions.
I still have many weapons in the Xunlai pending to update in the Wiki, I have to find the time, but I already updated 90 or so, so patience and step by step.