[jcm4ccc]

[ QUOTE ]
Basically, what I am visualizing in my head is a line graph that shows entry/rebuy purchases intersecting with cashes. At some point the number of purchases exceeds the likely cash return. Finding a way to invest optimally for each set of conditions would be very helpful.

[/ QUOTE ] You can't get that kind of graph, because you are thinking about this in the wrong way.

Your question is (or should be): Is it profitable for me to invest $20 in rebuying 3000 chips?

Here are 2 situations: You push 4 of your first 20 hands and lose everytime (let's say that every push was +EV--you are just having a bad run of cards). 10 minutes has passed. Should you invest $20 to rebuy another 3000 chips?

OR

You push only one hand--the 20th you are dealt. 10 minutes has passed. should you invest $20 to rebuy another 3000 chips?

You should see that the answer is the same. It doesn't matter that you invested $80 in one situation and $20 in the other. That is completely irrelevant to the question. You are faced with the question as to whether you should invest another $20, and you have 50 minutes to rebuild your bankroll.

The better way to approach this question is to determine beforehand how much you can invest in the rebuy, and to stick to that.