Black hat said at least $5 transaction fee for $100.
Would you mind quoting me, to see where exactly do I say that?
If there is an exception he omitted he should own up to it and provide that source of information instead of pretending he gave me a different figure.
Everyone can pay 1 satoshi for an off-chain transaction, as long as they'll pay two on-chain transactions for opening and closing a channel. This means that unlimited transactions between two parties can be made, by only broadcasting two transcations.
And it gets better! Lightning nodes can connect with each other forming a network of users that transact off-chainly. Not strictly two parties!