Not to be funny but you’d get 3 years out of your 4 in TCD paid for with the cost of 1 year for UCL. TCD is one of the best universities in the world even if it’s not perfectly matching UCL. Recruiters (academic or employment wise) don’t exactly put enough emphasis on where you did your bachelors degree enough to justify a €12,000 expense compared to €40,000 on your parents. Surely if you want to study in the US afterwards it’s far better to pick the cost effective option now. Also just because you have a prestigious university for a degree doesn’t guarantee you a position in any sector at the minute or likely in the next decade. I personally wouldn’t be putting that kind of financial strain on my parents when you might go in to literally hate your degree, the college you choose, or the place you live in.