Target has this official charging dock for the Switch Joy-con for $17.29, $13.83 after 20% with Target Cartwheel discount, until 10/20/18.
https://www.target.com/p/nintendo…A-52101562
Here’s the cartwheel link:
https://cartwheel.targe
Must add it in your Cartwheel first. Just signup for a Target account or login to get the cartwheel discount.