Macbook keyboard some keys don't work, how much will keybard replacement cost?

Details: F1, F2, (plus sign key), Up arow, right arrow, and a few other symbol keys dont have any effect when pressed.

Also, the trackpad seems to have a weird cracking sound every now and then.

My macbook is a white macbook from late 2010 I think. It has a 2.4 ghz cpu and nvidia 320m gpu. Not sure the exact model.

how much will apple store from square one charge to get keys fixed ?