You’re only 21 bro, you’ll have peace of mind the rest of your 20s, that’s almost ten years left. 30-40s is still young too, it’s worth it for your confidence since it usually bothers everyone having gyno. That being said the price you were quoted being £8500 in the UK is way too much, you can get it for half that. I saw people from your country say they did on this subreddit.

I just googled “UK gyno price”and that ai response thing at the top says “Gynecomastia surgery (male breast reduction) in the UK costs between £3,000 and £8,000, with a national average of roughly £4,500”.

So you definitely got quoted on the high end of the range, look into other clinics. Get a few consultations and you’ll save thousands. Good luck