Ask HN: How do I earn money online just to buy myself a gaming computer?

You seem to know your way round words so I'd advise freelance writing. Submit a few articles to a few places that are relevant to your interests and fairly current. Naturally taking time to get a feel for the style on the site. Make sure the editors are aware that you're giving them free stuff as a good will gesture and are available for more content if they need it. You should be able to get to $300 this way fairly easily, but it may take some time for responses, and a few rejections if people don't like your writing, but eventually you'll get a few gigs, maybe some steady ones, for monthly, weekly articles.

If you think you can write something good enough (and it's not that hard to be better than 90% of the target audience) then it'd be a nice quick way of getting the cash.

Create something cool and fund it using kickstarter? Though it's hard to offer advice without knowing your skillset, what are you good at? :)

fiverr (http://fiverr.com) might be a good place to start. There are plenty of people who want small jobs doing, particularly things like researching or writing small articles for blogs.