Budget Value Formula

[mlbdc2012]

I have a budget worksheet that I'm working with that needs a formula to calculate a value based on how many # of participants total are entered.

Each participant has been assigned a predetermined value based on a $100 budget and a default of 20 participants. My question is what if someone's example is more than the default 20 participants and I still have the same $100 budget. How do I then create a formula that automatically assigns the extra participants a value while still staying within the $100 budget and adjusts the participants who already have a value?

In addition, how do I create a formula that will adjust the current values from the question above if someone's example budget exceeds $100?

Any help would be greatly appreciated. My worksheet is attached. Thanks!