The cost of using Visa and MC is huge. Shops must buy a dedicated terminal which costs at least $300, and there's a higher fee to pay for each transaction. Then there's Visa which I'm sure has back office with servers in every country the service is offered. We're talking of a network with several thousands dedicated servers in it. This wasn't made in a day, and it took billions to build...
In Bitcoin system,the number of transactions per ten minutes is about 200 times.In Visa clearing system,the number is millions.
Bitcoin system is clearing system,but visa is not just clearing system(BASE II).
For example,if you lost your visa card,you can contact to visa,let them handle the problem.
you can also save money when you go shopping.
It need money,but it is not the cost of visa clearing system.
Servers in visa clearing system just process transactions,but in Bitcoin system,Servers also do hash race,and just one servers' working is effective at one time.
If there is no block reward,the transactions fee would be about 30 dollars in Bitcoin system.