Honestly I think it depends on OP's career goals. I'm a lawyer, and unfortunately law as an industry (especially City law) is quite prestige conscious. A good number of my interviewers (both for entry level and lateral positions) remarked on the fact that I had gone to Oxford for my undergrad and masters. Of course, I don't think it will save a candidate who is otherwise terrible, but it might tip the balance for someone who is borderline, especially earlier on in one's career.
As a former international student, I think Oxford is absolutely worth every penny (both from the pay potential and education quality perspectives), and I'm very grateful that my parents were able to financially support my education. I really enjoyed the tutorial system and just the overall intellectual stimulation and opportunities. Overall, I had a very happy and productive 4 years at university and would definitely make the same choice again.