I was thinking and while I do like the concept, the interesting thing (and maybe problem) is that it is statistically anomalous.

Suppose you have 5 options and 1 price.
The first person's chance is 1/5
The second person's chance is 4/5 times 1/4 =1/5
The third person's chance is 4/5 times 3/4 times 1/3 =1/5
The fourth person's chance is 4/5 times 3/4 times 2/3 times 1/2 = 1/5
The last person's chance is also 1/5

However, in the case of the grid the second person doesn't pay until the first person has tried and failed. This means that the chance goes up until a pot or price is found and so on. This means that it can be statistically calculated when it is the right time to play.

This is not necessarily problematic (people still play blackjack without counting cards), just thought I'd let you know.

If it becomes a problem, the effect can be countered by providing more multipliers in the beginning and taking them away after a certain amount of blocks are removed.