We just bought some property and needed both NIE /Green card and Passport.  Notary told us without the NIE/greencard it is now not possible to purchase anything.
However Getting a replacement I believe you need to provide all the same paperwork that you provided the first time around. And takes the same amount of time and stupid o'clock visits to the office in Tortosa Correct me if Im wrong though.
Good luck with your purchase.
Sarah