Hello,
I am not sure I am following you—
Fixed: amount ALWAYS given to the vendor. So if the fixed was set to $5 in your admin, and the vendor’s sale was $10, the vendor would receive $5. If the sale was $20, then vendor would receive $5. If the sale was $100, the vendor would receive $5.
Fee: Amount given to Admin on every sale as an additional fee on top of commission setting. Fee is deducted from the vendor’s Commission. So.. if you have your commissions type set to only fee, and the fee is $2, then no matter what you vendor sells, you get $2.
Percentage + fee: If you has commission % set to 50 (50%) and a fee set to $2… your vendor has a $20 sale.. your vendor would receive $8 ($10 = 50% commission minus your $2 fee = $8).