PPP is only relevant if your typical purchase is similar to that of the basket of goods used to calculate PPP. An iPod or a Toyota will still cost the same - irrespective of PPP - since they are global goods. (In fact due to India's laws they become much costlier in India with around ~30% increase if you convert money.)
True if you consider global goods. But for things that are produced within India PPP is relevant. Then again - it doesn't make sense comparing PPP when you are trying to rank economies on size.
