Is it harder to get the grades at Oxbridge?

Cost to who? And what has exam structure/style got to do with accessibility?

please explain.

Bloody hell you are stubborn. Cost to the applicant. Someone has to pay for the materials to be produced and marked: that's why A-levels and GCSE's cost about 20 quid a pop. Accessibility involves how easy it is for foreign applicants to take the exam: A-levels are very inaccessbile, and hardly anyone takes them who doesn't study them for two years; SAT's, however are taken in a huge range of countries by applicants who do a couple of hours' preparation.

Anyhoo, I've clearly nothing like your stamina for arguing this point, so I'm giving up. Yes, they are flawed, but in the circumstane they do a pretty good jobb and help a lot of people show their potential who could not do it under a more precise but less accessible exam structure.

Saying it's easy to get 700+ is akin it's saying it's easy go get a B at A-level, and doesn't mean much. Secondly, universities are aware of repititions, I think; they're certailny aware of those who only do exams once, and thus they can factor them in. I may be being excessively positive here; I just think SAT's are given less respect than they deserve.

SAT's, however are taken in a huge range of countries by applicants who do a couple of hours' preparation.

Actually many American schools offer entire courses on how to take SATs, and tutor their strong students for up to 2 hours a week in techinique and past paper practice. So no, the top students in the US are trained for the SATs just like any other exam, except for the fact that the verbal is a glorified vocabulary test, and maths is a glorified arithmetic test.

Because they are culturally and linguistically biased. It is that simple. If you claim otherwise you have obviously not seen how badly students of other linguistic and cultural backgrounds are disadvantaged.

Aren't the SATs primarily concerned with showing universities the level at which you potentially can perform in an English-speaking university? My mother tongue is Norwegian, but I don't think my lack of abilities in both written and oral English should make it easier for me to gain admission to a course - after all, disadvantages to people not having English as their mother tongue will still be present when they enter university, and if they struggled in an admission test, they will also struggle during the course. I personally feel that if any universities I'm applying to are unsure about whether my English skills are below the standards they should be in able to cope with the course, they should reject my application.