So, I’m having trouble with a lot of your reasoning.
It seems that you’re willing to spend a ton of money for lifestyle factors, but if that’s the case, why not just save the money and vacation across the US (or Boston if you like) during a gap year? You’d probably still come out ahead financially.
I agree with @collegemom3717 about how US unis would be perceived. Unless you attend an Ivies/equivalent tier (and maybe near-Ivy research powerhouses like UMich), most Brits wouldn’t understand why you’d spend a ton more to go to uni in the US. Take UCSD. I may see them as equivalent to Warwick. Most Brits probably would see it as closer to Newcastle or Aberdeen (if they even have heard of UCSD).