higher multiple when ~100% seller financing

The question and shared information here is appreciated.

Seller Financing and terms are a way to do two things. First, you can reduce your debt service by agreeing to reduced interest rates (see @sean bressler above), which gives you the ability to service slightly more debt and therefore pay a slightly higher price. Second, sellers usually (not always) are more lenient than banks when you come upon hard times. Banks have a set playbook and usually perfect their security interest through a UCC filing. Sellers sometimes don't. That allows for some flexibility during repayment.