Non-visa national applying for entry clearance as a student visitor in the UK?

I am a US citizen studying abroad in England this semester. Because I am a non-national I have the option of applying for entry clearance as a Student Visitor once I am in Heathrow International Airport. My question is whether or not there is a fee associated with getting my Student Visitor Visa (SVV)? I know it costs �70 to apply for a SVV through the British Embassy in my home country, but I was curious as to whether that same fee applied if I got my SVV in the airport???