There's no way Tesla will meet their cost targets unless they want to take a loss. First, their manufacturing facility is thousands of miles from existing manufacturing base. Suppliers may be able to produce the parts rather cheaply but transportation costs will inflate the price. Second, they want their suppliers to build new, Tesla only facilities close to the mass production plant. Suppliers are not going to eat that cost for the privilege of doing business with Tesla, which even at their exaggerated sales expectations will still only be the 4th or 5th larges automaker in the US. That means overhead costs will be through the roof initially, driving up part costs.
I fully expect them to eventually hit their target, in 5+ years.