Nidalee or Lux? League of Legends

Hey guys,
I'm at that moment again where I reach a certain amount of IP and have to decide who to buy. This time, I'm at 3150 IP, and my choices are either nidalee or lux. I've played Nidalee a lot before (when she was free and I bought her on my smurf) and I think she's really fun and cool to play. Lux seems really cool too and she has been recommended to me many times before.
Before you vote, take a few things into consideration:
1. Damage of the champion
2. Sustain of the champion
3. How fun the champion is