T-Mobile has announced it will offer the 16GB Nexus 5 through its online store starting November 14, and that T-Mobile retail locations will start carrying the new Google handset on November 20. The T-Mobile Nexus 5 will be $42 down with 24 monthly payments of $17, for a total of $450 over two years. That's $100 more than you can nab the same model directly from Google Play.
It's not officially known why the phone will cost more through T-Mobile, but a representative did tell CNET that it pays full retail price for each unit. This suggests that Google is offering a subsidy to customers who buy the phone directly from Google Play.
T-Mobile did not announce any plans to carry the 32GB model in the future.