Hi Alberto, , I appreciate the discussion.

I work primarily on low level where the Dapp actually calls the REST api to access the blockchain. There are no signatures involved in the REST api calls.

You can get the gas of your contract or each function by running a private Ethereum node and calling - method-:eth_estimateGas ,

In the case of yuni that you quote the user has to pay with yuni tokens which may be more costly and slower than the gas paid if calling directly.