Unique ideas for party?!
Answers:
WOW. This sounds pretty big. That's a big budget.
First off, you will get a lot of comments from repliers tell you not to drink and blah blah blah. Just giving you a heads up.
Anyways, there is always the theme party idea. I am in college and they are quite popular. In my source, I put a link to a site that has some good ones. Obviously you can decorate your house to go along with the theme using your budget money. I personally like a beach party theme.
For drinks, you should make a crap load of jello shots. Like a crap load. They go really fast at the college parties I go to. No need to make them insanely strong either where they dont taste good. They can still taste good and be strong enough to get people drunk. I've been to a party where everyone takes a jelly shot when a certain song comes on over the speakers. ....Obviously getting kegs is a necessity with that many people. For a change, I would also make jungle juice (posted link below how to make it). Jungle juice is a real popular drink that almost everyone enjoys. There is also "get laid lemonade" you can make (link below). With 300 people, you would have to pay some brand new trash cans and make the juice and/or lemonade in it.
http://www.collegetips.com/college-parti…
http://www.drinksmixer.com/drink7799.htm…
http://www.drinknation.com/drink/get-lai…
when you take part it will be unique idea for you.
Way to big for a birthday party..
Try a Banquet Hall