For leveling, you don't need the reusable for each tier. I got the reusable medpac each tier, and every other tier for a stim, alternating with an adrenal. So, for the third tier I got the reusable medpac, reusable aim stim, and used my second tier armor adrenal.
Once you get to implants, I would highly recommend you do not bother even going for the blues. You get new implants every 4-5 levels anyways that are even better than the purples. If you have extra mats from just leveling Diplomacy and doing ZERO Bioanalysis missions, you will have plenty of money. I had over 400k after training everything at 50, including the mount training and a 99k mount plus an extra bank tab and three bag slots.
Once you hit 50, be aware that the Rakata reusable medpac, stims, and adrenals each take a mat that drops from Operations (all bosses) and hard mode flashpoint end bosses only. All crafting professions require these, so good luck on your rolls.
Implants at 50 (technically 49) can take forever to get the purple version. I RE'd 35 blue versions of my implant to get the purple, but have since gotten four other purple implants with a total of about 30 RE's. So, RNG, but definitely took more attempts that stims/medpacs when leveling.