Although it does require a T3 Spire, you don't have to be in a fleet with one. You can get an invite to another fleet's Spire and buy it at their tailor. It doesn't cost provisions either, so your own fleet can have a T0 Spire and you would still be able to pick it up.
It doesnt look beautiful to me, just the opposite. Same for almost every custome of every fleet holding. I wish i could use the spire skirt custome, but since it is glitched as hell (of course, the best custome piece is the more bugged..), no costumes of the fleet holdings are worthy, none of em.. (well if they could be free, they will but its not the case lol.).
Comments
The Dyson Researcher Uniform.
You must be in a Fleet with a Fleet Dyson Spire T3 and unlocked Tailor.
Then you can buy the Uniform at the Tailor for .... Fleet Credits and ..... Dilithium. (I don't know the amount of the FC and Dil.)
Edit: here some infos. http://sto-forum.perfectworld.com/showthread.php?t=932941
Edit2: with some infos from JoeJing, the designer http://sto-forum.perfectworld.com/showthread.php?t=1046801
Mine Trap Supporter