That assumes that there's only one chip in the server (unlikely with 36 vcpus listed for C4), that you're happy with using a desktop chip with no ECC for Hetzner, and your pricing doesn't consider reserved instance pricing for C4 which costs much less than $1300.
Most of the servers on that page aren't even running ECC RAM. The only one listing ECC RAM is the E5504 which dates back to 2009 whereas C4 is running the fastest Xeon model available today. The rest of the list is Intel Atom and i5 and i7 desktop chips. 60% of the server types on that page are also currently out of stock.