I guess you never been UK before.

Snow?
You barely see the sunshine for the whole year. Sunshine is something premium/luxury at there.
I only experience once snow, just barely last for 10-20 minutes.

Winter is not something enjoyable, if you have been there before.
The "cold" make you don't want to go outside. It is not like in air-cond room at all.

Please focus on your consideration on your 400K loan issue.

Whatever weather shouldn't be in the consideration even minor one as well as those culture issue. If one has the luxurious choice i.e. have money, then different story.
Fyi, UK weather is not something "enjoyable"

Tax rate is 40-50% there, so even your wages is high, take home wages might not.

My experience
Food was cheap there, relative to their earning, as a large loaf only cost 12p (which last me 3-4 days) at that time (I believe it is now cost more but still cheap relatively to there), frozen pizza 1 pound.
Room will be the single most expensive expenditure there for living expenses.

I do hope you consider well, as this is just an undergraduate degree in economy, if like those medicine, specialised field, then it might have a good case of taking up such a loan, but economy degree can take 1 year in post-graduate as well. While in real working environment, good degree in economy doesn't make one a good economist. All financial and investment abnks are looking for good performance, good experience and track record person in head hunting.
Degree is not something very important after one involves in real working environment.
After all, NUS is not something bad to start with as well.

It is not like must have 400K loan in order to get a degree or risk of no degree at all.

All still depend your decision as taking different path will lead to different destination. There is no guarantee good degree ended good career or good life afterwards. Some without degree can be even more success in real life career.

Anyway, just my view. Don't mean to encourage or discourage on your decision or intention, all depend on your thinking and decision. Just throw out some experience and view.