The Logic Boards and Top Case Assemblies for the 2011 model and 2012 models are not compatible. While the mounting points are nearly identical, one of the mount points may only differ by 1 mm. Plus the Display Assemblies between the 2011 & 2012 models are not compatible. The product information appears to only reference 2012 as well which confirms my suspicions as well.
Plus like the others have said, the price is way too expensive. You can probably buy a whole 2011 laptop for that price. Or have the old Logic Board repaired...usually will cost about $300 US unless it has a GPU failure. You must be careful who you get to repair it since there are many people who don't really know what they are doing so make sure to find a reputable repair vendor.
You also need to be careful to make sure a firmware password lock is not enabled and to make sure the Logic Board is still being managed by a previous owner. You won't be able to fix either issue. Plus many 15" models are known to have GPU issues. I would never risk spending money for a 15" model laptop.
Personally I would not spend any money on this laptop even though I do like to keep older hardware working.