Cheapest area of UK?? For staying a few months?

Hi everyone!!! I want to go to UK to improve my English and I'd like to know which is the area that has the lowest cost of living. South or north?? Wales?? They've told me that Scotland is quite expensive, but I'd like to have a second opinion...It's my first time in UK so I want to have a good time. Please help me, and try to be impartial...I don't have much money to spend, I don't want to spend all my money in accommodation or food. Also bear in mind that I plan to go in the summer. Please help, only you can help me...Thanks a lot.