I am an international student and I got an offer to pursue a PhD in a really good university in the US (it's always among the top 5 in all rankings). I tend to like more experimental physics but I'm not dead set on it. I also got offers to do a theoretical one-year Master's degree in Oxford and some other English universities, but without funding!

I am international so I have the most expensive tuition fee.
I think I can pay this, using a combination of savings and loans. In the scenario where I have money to spend: is it really worth to pay for the Master's degree and defer my PhD for the next year? or should I just go straight to the PhD? Anyone had a similar experience?