Is it better and cheaper to plan a trip to Tokyo yourself or through tour packages?

I want to visit Tokyo in Spring of 2015 for 10–14 days. I have specific places I would love to see and do. Tour packages have a mix of things but not everything that I want.

Would I be losing a lot more money if I planned the trip myself?
Would it be that much stressful if I didn’t have a tourguide to translate and direct me where to go since I don’t read Japanese?