The Pleiades seems like a good place for the anarchic "Gold Posse" type groups (which to me seem like the Freedom/Anarcho-liberal types rather than a gang or crime syndicate) to set up mining outposts.
A lot of hot stars with metal rich and metallic belt and metal rich worlds, the area could become Elite's version of the "Frontier Gold Mining Town"
Heck as Bam Said, the place could Start as a Flotilla of Type 9s 7s and Anacondas where you would fly to and deliver the construction materials to and if successful, the first out post appears.
You could fly out with a cargo hold full of Machinery and parts and it gets traded for Gold and Silver and such that you fly back to civilized space to sell.
A long haul but would really make it feel the the construction of a [Frontier Town] Deep space outpost.
In my opinion it should be more a non-governmental/corporation effort to begin with, with the Anarchic faction in control then one faction each from the remaining four Alignments - Federation, Alliance, Empire and an Independent (Pleiades Union).
This way people can have petty squabbles over the control of the systems as a side activity as well.
Depending of the New Mission system, it would be awesome to have contracted Long Range Supply missions, such as;
Bring us 1000 tonnes of each food group (or quotas of Machinery and Mining tech or Clothes and lifestyle goods) for a considerable reward (after all it would be a 600 light year round trip each time to the garden worlds) but you would be bringing back the minerals and rare metals to civilized space on the return trip.
As the network of mining outposts grow, their could be a CG to upgrade one to a Refinery (and perhaps a Coriolis)
If the Independent (Pleiades Union) Faction gets control over a majority of the systems, it might spawn a new Power
The Other Major Powers have their Proxy wars, and the Anarchic Faction just want to be left alone to do their thing
As(if) the outposts become more civilized with the rule of Law, and we have passenger missions, it could be a tourist destination, being a Nebula with numerous Black Holes.