Not all sites deal with transactions (ex: my personal site). This would pretty much reverse any adoption rates TLS has. (who wants to pay >$200 for a certificate?) For example, Wells Fargo has like 840 billion in loans. They obviously don't want to pay $800 billion for an SSL certificate, and they'd lose that $800 billion if one file is compromised...

Right now, you can essentially pay to be a certificate authority. This just allows you to pay per site you want to attack.