I would recommend buying it for crystals. Farming the ships for it takes a long time, becouse they are still not accelerated, if you havent allready started it, and will extend the SLKR grind in general by around 4-6 months.
So unless you rly want to get the ships, its faster and more efficient not wasting energy on all thoose hard node farms, and use that on gear, and just buy the finalizer with crystals.
In general, for fleet, just get geos, vulture droid and hyena bomber. Then get malevolence as soon as you have the get2. Also makes your guild happy, couse geos get wat shards.
And stay the fuck away from the rebel fleet. It sucks. Not becouse its bad, but becouse to get it good, you need to put in like 2-3x the investment compared to a negotiator fleet and 4-5x compared to a malevolence, becouse all thoose ships in that fleet have so many more pilots, and you do need to relic them, to get that fleet working properly. and even then, its worse than either negotiator or malevolence.