I have seen the green/black saber crystals from the Razer peripheral promotion, and I was wondering what the stats are. Are they like the yellow/black color crystal? Can you improve its stats, or are we stuck with low stats?
Originally, there was only this item, which is +4 endurance, exactly like the original pre-order crystals.
However, it seems that Bioware has now added a pre-order vendor who sells high-level versions of the yellow-black crystal. It's possible they might do the same for the Razr crystals in the future.
As of Patch 1.2 you can trade in the original +4 endurance crystal and 250,000 credits for one of these level 50 crystals:
You get them from the Mods vendors on Coruscant and Dromund Kaas near the Market kiosks. The SE versions are slightly lighter/yellower in color than the Rakghoul Outbreak event crystals:
You could also get four cheaper +16 level 31 black/green crystals from that event.