Emma is organizing a charity event and needs to order t-shirts. The cost for each t-shirt is $15. The supplier offers a 20% discount on the total cost if Emma orders 50 or more t-shirts. Emma calculates that she needs exactly 50 t-shirts. How much will she save by ordering 50 t-shirts at once with the discount compared to ordering them individually? Let's think step by step and output the final answer within \boxed{}.
user