Most Helpful Girl
I'm not telling you Prom is going to be the best night of your life and it is really worth it, but nothing looks better than a well fitted dress. It's also a bonus if you aren't having to worry about your dress falling down all night.
Personally I think it is worth it to just get it tailored. The end result is much better than cheap patch up jobs in my opinion. Unless you are extremely talented at sewing or someone else on this site is a miracle worker, get it tailored so your prom pictures can really show how beautiful you are when you look back at them.