I like the simplicity of a marketplace like that, though it does open up lots of market manipulation vectors / black swan events if you parameterize it badly. You could pretty easily have gas bubbles that cripple the network, and it seems like there would be feedback between gas price in such a scenario and ETH/USD exchange rate (since gas price impacts network usability; I see it as similar to oil price and the stock market, but gas in ETH is a much more fundamental resource than even oil in industrialized economies).
The social cost curve @vitalik has in the paper would probably be argued by a lot of for example Bitcoiners to not be steep enough; at some point large blocks could definitely become catastrophic in PoW, if e.g. censorship results in a network partition.
Most of my comment specifically relies on the difference between UTXO storage and computation. Storage seems to require rent, computation does not. Computation is a cost paid once by un-checkpointed validating nodes and peers on the network at the time of the transaction, where storage is persistent and must be kept in a fast-access medium for security. It is an ongoing cost for every actor on the network, so I don’t think the same mechanisms can be used.
Also, just to clarify, I’m far from convinced GasToken is a net positive. I think GasToken is an important experiment, and something like GasToken could be a net positive. But there is a lot of modeling to be done before I’d personally be convinced of the optimality of any mechanism (even defining what that means is highly nontrivial).
My ideal market for both storage and computation would definitely include limited guaranteed issuance and restrictions on redemption that would enforce the lack of a network-killing capacity spike, and would also attempt to enforce a large percentage of capacity available on the spot market to reduce the profitability of cornering the market. Limited issuance into the future should allow for enough liquidity to extract useful pricing information and allow for large players to hedge risk while not overselling capacity.
This is all somewhat separate from the “rent” issue though, and whether to have cash-backed extra-protocol futures or computation-backed in-protocol futures is an open question. I think most would prefer the former for simplicity; curious to hear what people more versed in commodity markets than me think about that.