As long as you're cutting into your Essence, you should look into other cheap augmentations. Folks have already mentioned the cerebral booster. The trauma damper reduces Stun damage by 1 box, which will also help you handle drain. And you can use sensor implants to target spells, so invest in cybereyes, -ear, radar, whatever.
radar sensor (rating 4): 0.3 Essence, 12,000¥
cybereyes (rating 2) [w/eye lights, flare comp., low-light, thermographic]: 0.3 Essence, 4,250¥
cerebral booster (rating 1): 0.2 Essence, 10,000¥
pain editor: 0.3 Essence, 40,000¥, 5 BP (Restricted Gear PQ)
trauma damper: 0.2 Essence, 40,000¥
Altogether that's 1.0 Essence (bioware + half cyberware) and 106,250¥. If you care more about Logic skills than drain, you could swap out the trauma damper for a rating 2 cerebral booster. That has the same Essence cost but will only set you back 76,250¥.