Fixed fees aren't that bad

[mratsim]

A transaction has a fixed cost to the network, the fact that there are 3 more or less zeroes will not cost more compute power.

[vbuterin]

Why can’t tx fees be determined from a % of the amount of ETH being transacted, regardless of the USD price of ETH?

1. Fees like that can be trivially circumvented by putting the ETH into a wrapper contract and trading an ERC20 token which is backed by the ETH
2. Many kinds of transactions don’t even involve sending ETH at all; how to value those?

[MaverickChow]

Don’t all transactions involve ETH in gas?

[haokaiwu]

Don’t all transactions involve ETH in gas?

They do, but they don’t all involve a non-zero amount in the “value” part of the transaction, which is what you used in your example. Transactions to contracts often have zero ETH attached as part of the value. To use your example, how would we calculate fees for a contract transaction that transfers zero ETH if we take .001% of the transferred amount? What about a transaction that transfers tokens, not ETH?

It quickly gets complicated. Either you charge zero for these transactions (which is untenable), or you create a second system to deal for these situations, which adds complexity to the base layer.