The math is fine: if 10 million coins are in existence, in order to reach annual Visa volumes a coin needs to be worth 40000$. Proportionately less after more coins are minted, proportionately more if the payment volume rises. The mining revenue would rise to 1 million USD/block in 2013 - 2016, and the miners will use those earnings for rigs, electricity and profits.
The 1000x apparent inefficiency as compared to Visa has nothing to do with the actual efficiency of the Bitcoin payment network, rather to the particular way coin minting is performed. If Bitcoin achieves Visa levels after the initial coin distribution phase is completed (a few decades from now), the mining revenues will be much more modest. The 1000x factor is true today, and will halve every four years.
If the math was right and BTC cost was 1000x VISA cost and visa has a 4x markup then BTC price to end users (non-miners) would be 250x as high as VISA even if miners worked for cost. That is obviously untrue.
You are not accounting for the hidden revenue that seigniorage generates. Since Visa works with national currencies it does not have this revenue stream, so all it's markup is passed on the the consumers.
When an investor buys bitcoins for the first time, he enables miners to burn those resources in their mining rigs and mine a shiny new bitcoin for him. The resources are forever wasted but apparently he still "has the money" in new bitcoins - a curious case of having one's cake and eating it too. Conversely when Bitcoin will fail (as all human endeavors eventually do), someone will be left holding worthless bits. So from the point of view of the participants in Bitcoin, the markup is deffered until the system is closed, whenever that may be - tomorrow or one thousand years from now.
From the point of view of the society, we are better off avoiding a proof-of-work monetary system, like Bitcoin or gold. If we can convince our governments to issue sound, non-inflationary fiat money we can put those wasted resources to better use today. It's travesty of our times that the resources saved by fiat money, instead of making the society richer, are siphoned by the rent seeking bankster elite.