Thinking about what the proposed values for N and the absolute rent rate would look like…
I think we can safely assume that much less than 10m ETH will go into expanding the state; for reference, 422k ETH was spent on transaction fees to date.
Also, for reference, the current cost of filling storage, assuming the current average gasprice of 12 gwei is:
- Storage key: 20000 gas -> 2.4 * 10^{-4} ETH
- Account: 32000 gas -> 3.84 * 10^{-4} ETH
- Code byte: 200 gas -> 2.4 * 10^{-6} ETH
If we want per-year prices, we can multiply per-block prices by 2 million; your proposals would give 4 * 10^{-3} ETH per account and 2 * 10^{-5} per code byte, so current prices would roughly equal prices for a month of lifetime in the new model.
I suppose that if we want to increase the gas limit to 40m eventually, while keeping storage size lower than it is today, something close to this level of repricing is the only way to do it…