How to avoid transaction fees

It seems the transaction fee problem was very early linked to the spam problem, but could priority rules also do the job? In the moment, I am thinking it is a far better option since it becomes a limitation only when the resource is scarce while the fee happen even when the blockchain usage is very low.

(I moved the message from the read-only archive category)

Calls consume the highest possible fee according to the benchmark, then refund the caller in a way that can be customized.

Maybe we can use this to refund accordingly to the total block load.

Transaction priority is determined by the pallet transaction-payment, which we already use. The current policy is ordering by tip. I guess we can also prioritize by membership.