looking at a used 2006

The 2G drivetrain has slightly more power compared to the Classic. Although the gasoline engine in both have the same basic design, there are subtle differences between Classic and 2G. The 2G hybrid system is also advanced with higher three-phase AC voltage used to drive the two MGs which results in more efficiency since less power is consumed by resistance losses.

 

Is the "inverter battery" the high-voltage traction pack or the 12v aux battery or the inverter and one of the batteries?

The 2nd gen also seems to have longer-lasting high-voltage packs than the 1st gen.

One little trouble spot on the 2nd gen is the engine water pump--it can develop leaks. Look down the left side of the engine for the large, black pulley near the bottom. If leaking, you should see some pink deposits inside the pulley or nearby, and sometimes on the underside of the hood. It costs about $390 at a dealer service department or $100 DIY to replace. That, and the 12v aux battery and tires have been the only items I've had to address since new.

I've been very happy with the 2nd gen--it's the ideal car for me.

 

price tends to depend on location, but it sounds about average. i would want to know why the battery was replaced and a complete service/accident history. all the best!