Im new to the game. Just hit 50 for the first time, and not playing with a group/fleet. The cheapest Ive seen the technician doff is around 3million. Most i have every had in this game is around 400k. So saving up to 9 million just for 3 doffs seems like it will take forever to achieve.
Run the colonization Doff arc in the B'tran cluster. Once you're finished, you'll have a repeatable mission that when critted yields a purple Tech doff.