Green Card attorney?

I just got my H-1 and thinking to apply for GC. I do not trust the one my company suggested because she did not do a good job for my H-1. Then my company say you can go Sheela Murthy, but it's expensive, around $6500. My question is how good is Sheela Murthy? And what's the general charge for GC? I am in NJ-NY area, I would appreciate if you can recommend any good attorney. Thanks!