There is also the possibility to form the entire block based on a single private key (0.2 BTC per block) or any single public key without private keys (0.05 BTC per block).
Demo (part of the block): ...
Why would one pay 50 BTC for a script that simply multiplies a scalar key by lambda endomorphism, and curve point field elements by beta endomporhism (for X) and subtracts Y from field order / negates the key?
Sorry to ruin your secret.