Right now, the original purchase price of one of these domains is ~4 years of fees on a traditional registrar. Let's round the transaction fee down to $10 for the sake of simplicity. If you update your configuration every two years (which seems generous), you'll break even in...six years? And that's assuming whoever made the contract doesn't take a fee.

This assumes Ethereum fees don't change. Proof of stake might affect transaction cost, but the trend right now is up and to the right: in one year the average transaction cost has increased two orders of magnitude.

If we assume the rate of growth of the average transaction fee slows dramatically to one order of magnitude every two years for the next few years, that means the cost of your domain will probably never break even (over a traditional domain) in your lifetime. Even if it only doubles every two years, you'll likely never break even.