Throwing my first "party" now that I moved into my own place. What are some affordable ingredients I should add to the shopping list?

Probably have a budget of ~$100. Definitely getting malibu, probably some beer as well. Already have some grenadine and maraschino cherries.What other ingredients have a fairly versatile "wardrobe" when it comes to cocktails? What are some must-have cocktails I should make? http://www.reddit.com/r/cocktails/comments/3givdg/throwing_my_first_party_now_that_i_moved_into_my/