You can take a 1/2 chance of winning 16 dollars, or a 1/3 chance of winning 81 dollars, or a 1/4 chance of winning 256 dollars, or a 1/5 chance of winning 625 dollars, etc. (1/x chance of winning x^4 dollars). Which do you choose?
I don't lmpw how the math shakes out, but at those numbers I go for the $625, the risk of missing out on a better chance at those lower numbers seems insignificant, I throw $16 down the drain all the time 😛