Thanks for all the advice.
I am planning on having a small seeded doubles mini (highest PDGA rating plays with the lowest PDGA rating). If there is an odd number of players, I was going to have the middle rated player play cali.
Based on the responses above, it appears that full payout is the most common, regardless of single or double payment. I will probably have the cali person pay the individual rate, get 1 extra throw per hole, and be eligible for 100% of the payout.