... The Rakata/Battle-Master weapons have the same grade/rank colour crystal as the Columi/Champ ones, grade 56, giving +41 stat, so the ones purchaseable at the Geologist are equivalent to the best available in game from loot drops.
Dev has also stated that the +41 will be the best for the foreseeable future, so don't worry about a +50 crystal coming out in 1.2 or 1.3. They said this in response to some people wondering if there will be a new credit sink crystal right around the corner.
After that though, who knows?
I might just buy a white one, although it's too bad they're BoP