Because ES cluster should not be on public network. If anything this is red flag for AWS. ES v8 there many improvments to security.
It cost that much because AWS is incredibly expensive.
It cost that much because AWS is incredibly expensive.
If a product upon unboxing promptly flops on its back with "come here internet" access controls, even if by good fortune it's saved by your network ACLs, it's time to put it back in the box and return it.