I agree with what others are saying here. Crafting is pointless in this game. There is no way to make credits from it.
On my server I've seen 1 other orange crafted pistol on the GTN since launch. I have made 4 of them myself, and put them up on the GTN to sell. I did not ask for stupid amounts of credits... just about 100k credits (considering that these pistols are as good if not better than the purples that were up on the AH for 90k credits) and nobody will buy them.
Armstech is one big waste of time. Investigation does not give you half the things it promises in the codex (I may have got 1 schematic in hundreds of mission runs from 1-50) and as for scavenging.. well, whatever.
Take Biochem and slicing, and you are golden. Anything else is garbage.
What also annoys me is that on our server at least you never see ANY schematics for any profs other than biochem or synthweaving. There has never been more than 1 page of schems on the GTN for each profession, wheras the two I named are usually 10+ pages of listings...
Er, drop rates fixed? much?