What are phase contrast and DIC? Do I need these?

These methods can produce quite spectacular images, but are also significantly more expensive. Low cost student and educational microscopes are not equipped with these optics. Most amateur microscopists do not own DIC enabled microscopes, some have phase contrast. If you want phase contrast or DIC, then it is best to talk to a larger microscope manufacturer about these possibilities. You might be better off first starting with a low cost microscope and then later deciding about whether these techniques are something for you.