IMHO, the 4x4 pricing is higher by 3-4 lacs. The 4x2 pricing is expected to correct this.
I think a competitively prized 4x2 is what the general public wants in a minivan (though Tata would like to differentiate it as X'over)
Also the mental block to spend 15+ lacs on a Tata product and still be forced to take part in community R&D must have played a major role in Aria's dismal sales.
If the top variants of Innova (4x2) and Aria (4x4) was prized the same, I'd gladly pick the Aria. I'm even ready to pay 30K-40K more for the 4x4 but not anything more...