Which fonts don't come with Windows 8 that would come with a new MAC?

I'm a beginning graphics designer and I currently own a Macbook Pro that I got in 2010 that is really on the fritz and basically I need a new computer.

I am comfortable using both Mac's and PC's, so I have no issue there, but I am worried that if I get a PC I won't have access to the fonts that I am used to using on a MAC (e.g. Helvetica, Futura, Gill Sans).

I am wondering what fonts come on a Mac that don't come on a new PC and how much it costs to purchase these fonts?