Right now, Amazon.com is selling the 36W Surface Pro 3 chargers for $38.00 USD ($42.50 including shipping!) Normally, they list for $79.99 so I wouldn’t expect this deal to last long.
UPDATE: As of 10:14PM EST, it looks like The price has gone up to $43.49 + shipping. Looks like they are trying to make a few extra bucks on the deal now. Still a good price, though.
If you want a spare charger for your Surface Pro 3 then you’ll want to hurry up and head on over to Amazon.com. As I write this there are only a few dozen left!!