I am starting at NAIA in South Carolina in October and was hoping that someone can tell me how much it does cost to live in the US excluding accommodation a month
How long is a piece of string?
Eat at McDs three times a day and you will spend $10. Buy food at the supermarket and live on bread and cheese and you will spend a little less. Cost of living the the US is less than the UK, but not by as much as most people believe, but South Carolina is can be considered cheap by American standards.
Beer in bars tends to be more expensive than the UK, but you can do a lot of damage for little money during happy hours. Remember to tip 15%.
Don't forget you need transport, public transport in the US is a joke, renting a car could easily be the most expensive part of your trip.
Call NAIA and ask.