How much should I charge to make changes to someones website for them?

I am studying for my associates degree in web design and interactive media. A professional has asked me to make some changes to their website. These changes include: Search Engine Optimization, Filming and Uploading at least two different videos, and adding sound to the page among other things. What should I bid it at?How much should I charge to make changes to someones website for them?$200 seems good.