Two reasons I would not purchase - although it's definitely a locomotive worthy of a Sunset/3rd Rail offering.
1) I own an MTH Premier model of Santa Fe #5012. It might not be up to the standard of a Sunset/3rd Rail version but it's quite satisfactory for me.
2) In view of 1) above, I cannot justify the expenditure.
On the other hand, I would purchase a New Haven I-5...
MELGAR