Once you reach 50 tradeskills are a joke. Everything you do just piles in the credits and with 5 companions you can max out any tradeskill, in a single session of play. The mission ones take longer, but not by much. If you really want, start with something like artifice, max it out on everyone while doing dailies and a few easy hard modes like BT and BP for the crafting mats. Build your Bind on Pickup Rakata items like the relics and dump the skill. Once you have all your end game items, then finish with biochem because it's the only tradeskill that requires you to actually have the skill to use the items.