~$200 (score: 8/10)
Realflight G2 has a pretty good helicopter flight model, and is a good simulator for learning non-micro helicopter skills. The helicopter flight model is probably best of all the flight sims mentioned here, and it will probably be good enough to practice 3D aerobatics.
I would recommend practicing hovering on the Impala model initially, then later when you acquire proficiency I would recommend buying the Add-ons 3 and practicing with the Raptor 30 model.
For some reason, many of the models in Realflight do NOT have the heading hold function enabled nor the revo mixing set up correctly. This means the helicopter will continually rotate and be difficult to hover. If you have this problem, you should select "Copy Model" and enable the heading hold gyro and also edit the radio to turn off the revo mixing. Add-on aircraft and scenery packs are available.
Futher information available from www.realflight.com.