I can imagine having a wallet with say a 1mil sats, and let's say the fee would amount to 30% of the value. In this case you could give the wallet seed in exchange for some other value proposition.
Exactly -- real-life xfer of Opendimes, or some similar thing, is another kind of L2. I think the xferring of seeds wouldn't work by itself, as without sweeping contents on-chain to another address both the seller and buyer would now have access to them. But that general idea will be important, I expect.