Seller finance concern

[Carole G.]

I am wanting to sell an investment property so that we get cashflow without the headaches of landlording.  The buyer is giving me enough down to pay off the mortgage I have on the property.  The buyer is not comfortable with a 10% of the outstanding balance penalty if they pay it off early, but as I look at it closer, even that is not enough for ME to be comfortable selling it owner finance.  I want the 10% penalty to help pay the taxes incurred if the buyer pays it off early by selling or refinancing.  How should I keep taxes low in the case the buyer pays it off early?