Its 20, 000 fleet credits and four fleet modules for the retrofit. You only need a Tier 3 ship yard. The majority of fleets have reached that. Thus, even if you join one temporarily, paid your dues and earned your fleet marks (would not take long for 20 thousand fleet credits, especially if paying into projects with Dill) you'd end up flying the ship of your choice within a reasonable time frame.
No plans on releasing the T5 version that was given away for free. Maybe it will be re-relaesed as a free ship again in a year or so, but who knows. As it stands, you can only obtain a T3 version for free by doing same mission as always. Personally, I'd get the fleet version! The Free T5 version was great, so the Fleet would be even better.
Getting into fleets is easy, dont waste your time paying a fleet for access to a tier 3 shipyard especially if you do not have fleet credits to spend.
"The world ain't all sunshine and rainbows. It's a very mean and nasty place and I don't care how tough you are it will beat you to your knees and keep you there permanently if you let it. You, me, or nobody is gonna hit as hard as life. But it ain't about how hard ya hit. It's about how hard you can get hit and keep moving forward." - Rocky Balboa (2006)