That's definitely a tall cliff, but there are other factors to consider besides height. People survive falls from incredible heights under the right conditions.
What is the landing like? Is it soft like sand or clay? Is it sloped?
Is the cliff completely vertical? Is it possible you could bounce on the way down slowing your descent, or possibly get stuck on a ledge?
Here's an article about someone who fell 300 feet and survived:
We report the case of a 28-year old rock climber who survived an "unsurvivable" injury consisting of a vertical free fall from 300 feet onto a solid rock surface. The trauma mechanism and injury kinetics are analyzed, with a particular focus on the relevance of body positioning to ground surface...
sjtrem.biomedcentral.com
That woman hit a rock surface 200 feet down, then continued falling another 100 feet to the bottom, landing on her feet on a flat rock surface. I doubt she would have survived if she had fallen 300 feet continuously and didn't land on her feet.