Can you appeal for more money or is this not a good idea?
You can always ask. But have a plan B if the school says no.
Some schools seems to have a reputation of giving more money if you just ask. Not a lot, but some. You need to have a list of reasons - big family, others heading to school next year, even something like extremely high utility bills last year. The school needs a reason to pick you over someone else.
What is the situation? HOw much were you given? What are your stats? test scores??? What is the upper quartile test scores for that school?