Assuming you're not in high school anymore, I'm guessing that you'd be able to afford a much higher budget than I. I work very hard and actually make quite a bit more than the average high school student, but I'd like to avoid spending more than $200 on one snake.
Then in that price range the best dark morph IMO is a Black Pastel, at that price you can pickup a female this season (which you might want to do just in case one day you plan on breeding)