Guild Milestone

Probably the first, real, guild milestone to reach is guild level 10.  Why?  Because this is when you can buy your first* airship - without using astral shards.

My one-man guild over on Argonnessen has been running heroic sagas with the intent of turning them in for guild renown at the next guild boost weekend.  With all my toons in the level 12 range, this means running Gianthold and the recently added "The Pirates of the Thunder Sea" sagas, as the other two heroic sagas are still too far out of reach**,  I've already complete 'Pirates', thrice, on normal (once on each toon), and just finished Gianhold, on normal, once.  But seeing as how I was already somewhat close to guild level 10, I managed to eke out enough guild renown in normal game-play to finally reach guild level 10.

I now have the smallest airship in the game.  Woohoo!

Of course, I don't have much in the way of amenities, but it's a start.

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* You can actually buy the largest airship in the game at guild level 1 - if you're willing (and able) to spend the astral shards for it.

** They are located in Eveningstar.  And even though, technically, one can access Eveningstar at level 1 (see the wiki article), some of the individual quests are level 19.  Not too mention these two sagas have 16 and 24 quests to run, and the other two only 10 (each).