International fees are approximately £8,000-£10,00 per year.
A person is only eligible to pay home fees (approx £3,000/year) for university if they meet the following 3 basic criteria:
a) must be a UK or EU citizen, or must hold ILR.
b) must have been living in the UK (or EU in the case of EU citizens) for the past three years.
c) none of the qualifying three years of residence can be primarily for education purposes (meaning, time on a student visa doesn't count towards the three years.)
That's basically it-
click here for the nitty gritty detailed rules.
A person on a work permit won't qualify until they get ILR five years after receiving their work permit, and spouses won't qualify until they have ILR and have been resident for three years.
So no, just because you get married to a Brit doesn't automatically mean that you are allowed to pay home fees, I'm afraid.
edited to add: the loophole that Kristi found definitely does exist at some unis, but I've also seen quite a few universities that have a separate fee schedule for part time international students (ie, those on spouse visas, or Brits who have been living out of the country for a while.)