How to calming sellers tax fears

[Justin C.]

Good day BP, I have a seller who would like to sell his 2 small multifamily buildings but is nervous about the tax burden if selling both in same year.  He has agreed to owner financing.  Would owner financing spread this burden out of the course of the term?  Here is the deal:

$140k purchase

$20k down payment

$120k owner finance 5% @ 30yr term; 5yr balloon

What would your 30 second sales pitch be for this?

Thanks in advance!