I bought the IVSO - only £7.95 from Amazon UK.
I expected it to be poor quality & just a temporary purchase until I found something better but, as it happens, I can find no fault with it & it will live permanently on my C
Not sure if links are allowed but I'll try:
Google Pixel C Case - IVSO Slim Smart Cover Case for Google Pixel C 10.2-Inch Tablet (Black): Amazon.co.uk: Computers & Accessories
Edit P.S: Oops, forgot there is one minor issue that could be relevant to any case of this design with magnets (although it shouldn't be considered a 'fault') - If, when folding back the cover to use as a stand, if you're not careful with how you do this (i.e. you slide the magnetic part across the back of the tablet) the tablet will ask you whether you want to turn on Bluetooth (simple OK/Cancel dialogue).
I personally don't find this an issue as:
a) If you fold without sliding, no problem
b) Hitting cancel is no big deal
c) The battery life of the C is so good that leaving Bluetooth on would only be an issue for the most demanding of users
If, however, these things an are issue for you, you need to choose carefully with any of these folding cases that claim auto-sleep / auto-wakeup