I'm a 20 year old student studying Graphic Design. I occasionally get clients who would like me to completely redo their website such as designing a custom theme, adding plugins and doing it all with wordpress.
It depends on quite a few factors:
- How much experience do you have?
- How much available time do you have?
- What do you like doing?
If you can't commit full time to a project during the week because of school, you can focus on one element of a site design, and outsource the rest.
Will you be customizing existing themes or writing new ones completely from scratch? Pricing will vary based on all of these answers, and it's a broad spectrum.
I also recommend figuring out the ideal rate for the lifestyle you have or want: http://www.yourrate.co.
Good luck - happy to chat more if you'd like!