I do the same thing, just not with Bio =P
I was doing that a lot with Archaeology Power Crystals for awhile as it seems like Grade 6 and 1 - 4 are always in great demand but grade 5 seems too common for it to be in demand. I'll have to experiment a bit with Slicing now that it has been brought up (Also with Grade 6 Slicing mats I have noticed the Augmentation Patterns you get sell pretty well too!)