Apple do still sell the old Magsafe 2 85W poweradapter. Availability may differ worldwide, but here is a link to the american Apple Store:
Apple 85W MagSafe 2 Power Adapter makes it easy to connect your MacBook Pro with Retina display at home or work. Get fast, free shipping when you shop online.
www.apple.com
But I would suggest a more versatile and economic sollution. You can get a
Magsafe 2 to USB-C cable or adapter. Combine it with a modern and versatile USB-C power adapter. Any poweradapter with 85W or above will work and not harm your MBP. It is also possible to use a USB-C charger less than 85W but charging will take longer time.