Resource-wise, a $2 transaction costs the same as a $1 transaction. So the current fee model is the most accurate.
What does "accurate" mean? There are two ways to approach this:
1. Tie tx fees to the network's actual costs.
2. Tie tx fees to perceived value of making the respective tx.
You have to ask why you would choose which approach.
Also, I don't want to pay 100x the fees for sending $100 as opposed to $1.
This makes sense from a customer's perspective. It doesn't make much sense form a business perspective. Any business, also Bitshares has to be as profitable as possible and you do that most efficiently by making the following ratio is as positive as possible: money made per customer interaction / degree to which the fee/price bothers the customer. The latter also has to include how likely it is that the respective customer will use some competing business, so at best you are as expensive as possible but as cheap as necessary to not drive people away from your business respectively to give them enough of an incentive to change from a competitor to you. The outcome of this equation might be that fees don't actually rise much if you transfer a lot of value because competitors out there (other crypto currencies) offer lower fees and high volume customers are valuable for your (exchange) business otherwise. But looking at it this way makes a lot of sense in general if you want to survive as a (decentralized) company. Money made from optimizing this equation then can be invested into your infrastructure (bitshares' workers for example).
Yeah, you're right.. it's about competition and perception. And it may work quite well for market orders.
But the sliding % scale sounds confusing.. wouldn't it be better to have a fixed % and a min fee? Or a tiered cost structure.
I still think for basic transfers, competition will soon drive the price very close to the true cost.
Also, in these cases it will not be possible:
- UIA's of unknown value (so it would only work for liquid, tradeable assets)
- Confidential tx's which hide the amount