aww man, why make the Scathach unobtainable? isn't selling HVB ships the whole point of the Prism Freeport? or at least one of its main uses?
I thought blueprints were the main point...
Anyway, the Freeport sells a lot of stuff it probably shouldn't. I never used the Scathach but the flavor text makes it seem like it's a one-of-a-kind technological marvel, so it would be odd to show up at some merchant, no matter how high-grade.
Personally I don't care, I never purchase unique ships. Since the Freeport isn't tied to any kind of progression and sells rare ships to anyone you might as well console command the Scathach in if you really need it in your fleet.