As most people know, London is expensive. Besides accommodation, public transport was also very expensive. As a student though, you can apply for an 18+ student oyster photocard, which gives a 30% discount. And since I lived in zone 2, I only had to buy a card for zone 1 and 2. I did not really notice that groceries would be more expensive than in Sweden, and sushi (although not the best) was cheaper. A friend also gave me the tip of buying a subscription at Pret a manger, which is a coffee shop franchise with stores all over London. The subscription costs 25 pounds per month and gives you 5 drinks per day. This was really worth it for me, since I would get at least one coffee from there per day, and there are at least 4 shops within walking distance from Guy’s campus. With the student card you could also get discounts to certain tourist attractions and also at some lunch restaurants such as Wasabi.