[FoxwoodsFiend]

Your answer depends on factors that you don't give, so instead (and hopefully more helpfully) I'll walk through an estimation.

Suppose that a top-30% player will hit the top 12% something like 1/6 of the time. This is probably generous to the top-30% player but is probably not too far off. The probability that this happens 5% of the time through 150 tournaments, or in 7 or 8 tournaments (let's call it 7), is:

(1/6)^7 * (5/6)^143 * (150 choose 7)

The first term represents the cashing probability compounded over the 7 times it happens, the analogous second term is for non-cashing, and the third term multiplies the first two by the number of ways in which it can happen.

I don't have a calculator handy, but it should be easy enough to plug in somewhere.

Please note how dependent the answer is on the probability of cashing. Also note that the probability of cashing is not perfectly correlated with player quality -- some great players don't cash much more than average, and some of the highest cashing percentages probably belong to players who are far from the very top.