Add Transaction Cost Field

Would it be possible to add an optional "transaction cost" field when creating a new transaction? Most of my payments include fees (e.g. bank or transfer charges), and currently I have to create two separate entries — one for the actual expense and one for the fee.

Having this as part of the same transaction would streamline input and improve data accuracy. Ideally, the total debited (amount + fee) could also show up in summaries.

Thanks!