Anker's USB-C to HDMI adapter is only $16.79 with code ANKER836. It's $24 without the code and has not had a direct price drop from that price in many, many months.
In The Wirecutter's roundup of the best USB-C adapters, they consider this one the best for anyone who wants to hook up a modern USB-C only laptop to an HDMI monitor or high-definition TV. Not only does this tiny adapter have a solid build quality and support 4K video and 60Hz refresh rates, it's also designed to work with the newer Chromebooks. Users give this adapter 3.8 stars based on 192 reviews.