I have advertised my half duplex as a lease option. I have a basic understanding of how lease options work, however, I am at a loss for how much I should credit back to the renter "purchaser" out of the total rent. eg. mortgage is for $1150 per month shall I set the lease option rent at $1500. This is $350 cash flow how much of this $350 do I credit back upon tenant exercising their purchase option.