2009 XWD 2.0T Rear Shocks

Can anyone tell me why the cost for the rear shocks for my 09' XWD 2.0T are significantly higher and harder to source, than the non-All Wheel Drive models?? Most research I've done thus far, has put them at around $500-$600 CDN per shock (The 'Stealership' quoted me almost twice the amount).

Or better yet, can anyone advise if there an alternative shock option that people have used with the same dimensions/makeup??

Thanks in advance,
Mark

I have a 2011 xwd 9-3 and both of mine blew out at 40,000 miles about a month apart... could not find an alternative shock that would work. About $550. USD each! And I do have a new spare...