i may be a bird in a cage but at least it's your cage

Also consider the new, ultra sexy AF-S DX NIKKOR 35mm f/1.8G

It's going to be about $200, but what you save on rental, you gain in field.
I have the 50 mm. It's a pain when you're shoved up next to the stage, because it shoots like a 75, and sometimes all you want is a slightly bigger field, but hell if you're giving up your spot, you know? Also, remember, used lenses rock.