I won't pretend to understand the US system, but in the UK...
You could have started and ended your post there. To paraphrase Douglas Adams, the university system in the US is almost, but not quite, entirely unlike university systems in Europe.
Tuition at my hometown college (University of Toledo, where I got my two BSs and one of my Masters) is currently $9200/yr, in-state tuition for a state-subsidized college. (This is not quite double what it was when I went there 20 years ago,
after adjusting for inflation, but the hyperinflation of tuition is a topic for a different time.) Room and board is a bit more than that, about $10k/yr.
If you're lucky, smart,
and poor, you'll be able to pull that tuition number down into the $2k/yr range, which you'll have to cover with loans. If you only fit one or two of those categories, you're probably going to be stuck with 4-5k/yr in loans, though the variance is going to be higher (see "lucky.")
For someone coming from even a middle-class family, living away from home is an expensive proposition. It's 20% of the median family income in the US, just for room and board, and unless your family has a ton of extra savings, that's 40k in non-dischargeable loans at 6% interest over 4 years. Note that living off-campus isn't likely to help the situation all that much; while your rent will be lower with a roommate, you're still spending money on furnishings and the like... and you likely won't be able to use student loans for it, where you might be able to for on-campus housing.
For someone from a poor family, loans are the only way to go, and they follow you forever.
Aim as high as you can.
https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equationYou can aim for the stars, but if you don't have enough fuel, you're going to crash, or possibly burn up in the atmosphere.
--------
So to speak to sudgy:
https://en.wikipedia.org/wiki/Multistage_rocketI've personally never heard of an undergraduate degree in particle physics; it's possible they exist, but that doesn't automatically mean you should go for it. I'd say that yes, get a BS in physics from your local university. Try to do some undergraduate research; if you're lucky, you may get paid for it, and if you're very, very lucky, you might have a paper with your name on it before your undergrad career is done. Then once you've burned through your first stage rocket, aim high with the second stage and apply to a bunch of grad schools, especially if your grades are great. You still might not end up in the most prestigious place possible--very few do so--but if your plan is to go into industry or practical research, rather than to attempt to go into academia, the pedigree on your diploma isn't nearly as important.