This is something that more players should be talking about, but the title alone might not explain what exactly I'm referring to. There are skins in the game that were previously obtainable but then were later made unobtainable either because of an oversight or or a misunderstanding, or possibly even a bug, I'll explain everything below.
Take a look at this: https://imgur.com/a/7zsyuqN
Charr and Asura versions: Light - Medium - Heavy (Biggest difference is visible in the light and heavy armor)
These armor sets were available as PvP rewards in 2014 but were removed after the reward system got updated, the CHEST PIECES(For Light, Medium and Heavy) were made available from the Guild Initiative Representative for 1 gold each, and I assume the other pieces of the armor set were deemed too similar to the Devout and Banded armor to be included, this MIGHT make sense with the medium set which is actually very similar, as you can see here: https://imgur.com/a/4LUUGQG
But it doesn't make sense with the light and heavy set, for example on the guild archmage armor, you can see that the mantle is actually missing a part on the front so that the guild icon, the cowl is bigger and has a different shape from the Devout set, and on the guild defender, the chestpiece is lined up with the legguards to match, if you try it on banded armor it looks completely different.
You might argue that it's still too similar despite all these differences, but there are a ton of armor sets in the game that have 2(or even more) versions with only subtle differences similar to the guild armor, though they are still obtainable in the game, these include but are definitely not limited to:
-Elonian Armor and Spearmarshal's Armor
-Triumphant Armor and Triumphant Hero's Armor(Severity changes between armor classes, with light having the LEAST difference between the two)
-Glorious Armor and Ardent Glorious Armor(Again, severity differs between armor classes)
Those are just a few examples, there are also regular skins with some modifications to them that then get sold -ON- the gemstore(Flamewalker and Mist Walker) as a completely new set, isn't it possible to do the same for other unobtainable skins or NPC clothes that can easily be turned into player armor skins?
Guild armor sets are not the only ones skins in the game that used to be obtainable but no longer are, we're still not forgetting about the amount of town clothes skins that were fit for every character and every race, modelled and ready to be added as new skins with very minimal effort from ArenaNet designers. I would even gladly pay and support the game to buy these skins if they get added to the gemstore, though town clothes probably deserve their own topic. There's a lot of demand for these types of skins that ArenaNet isn't capitalizing on. Simple armor skins that offer creativity with mixing and matching with other armor skins.
One other very unfortunate example of such armor is the Council Guard set, the version that players have access to appears dirty, torn, chipped and heavily damaged despite a CLEAN version being available in the game, it's worn by Seraph NPCs, Sylvari NPCs and Charr NPCs, it exists and is fully implemented in the game yet for some reason players can't have access to both versions, we only get the damaged one.
TLDR: My suggestion is adding the guild armor skins to the Guild Imitative Representative(guild armorer) NPC so they can be sold along with Guild Heavy Armor, Guild Medium Armor and Guild Light Armor. These skins are meant to match together and it feels like an extreme waste that such perfectly usable skins are unobtainable by players, despite being modelled and ready without any fuss or trouble, so why aren't they sold along with their counterparts? They already exist in the game, they can even be previewed in the wardrobe bank by any character race and some players even have access to the skins and can easily use them. Would it really be difficult to include the missing pieces of the set they belong in with the same merchant?
EDIT: The merchant that I'm referring to that should be selling the full set: https://wiki.guildwars2.com/wiki/Guild_Initiative_Representative_(guild_armorer) (Currently only sells the chest piece from each set, instead of the full set with the other pieces that are meant to match the chest piece)
Just a side-note, there's a lot of simple armor skins that players would love to have, and I would personally even pay to get for the sake of simple fashion and more creativity in mixing armor skins, a GREAT example of such skins is the top worn by the Shipwrecked Circus Treasurer, it's a simple tank top and wouldn't(I assume) require too much design effort to make it usable by players.
There's a LOT of similar armor skins that both the GW2 fashion and the roleplaying community would love to have implemented into the game as new armor skins, these include NPC clothes, deleted town clothing skins, simple skins worn by expansion NPCs like the shipwrecked circus, so on and so on. With some slight co-operation between ArenaNet and the GW2 community, we can make those skins finally available to players, in the name of FASHION!(And fun!)
All it would take to re-add these skins is simply making them purchasable from the Guild Initiative Armorer, they don't require re-modelling, they don't require re-designing, just a way to purchase them so players can use them and match them with the set that is already sold by the same NPC.