SDE vs EBITDA Multiples - Seller Financed Opportunity

I plan to submit a LOI for a home improvement / home furnishings / interior design business in the coming weeks. I have utilized a trusted contact who is a commercial underwriter (can provide contact info if you need one) to "spread" the deal and break out all financial ratios. There is a lot of noise when I search for the appropriate multiples in this space and I would appreciate direction from anyone who has direct experience. I feel it's important to note: -This opportunity is off-market and will be 100% seller financed. -We have not had a deep dive discussion on expectation of price to this point. -The seller has been passively running this business, < 15 hours per week for nearly two years. -The deal came to me through a trusted contact who was aware of the opportunity and thought this would be a natural bolt-on to an already existing commercial interiors business owned in my household (correct assumption). -The owner is excited at the possibility of transitioning this residential-focused business to an ownership team who can immediately open commercial channels. -I am satisfied with the trailing 36mo margins the business has produced. -Current employee base is experienced and tenured, evidenced by the continuing profitability as the owner pulls away. -COGS slightly higher than I'd like to see, but the business is somewhat over-employed at current given the owners passive involvement. There is ample room to grow before needing to add any additional employees. -This is a franchise location (see my previous post on the topic) -There is a manageable concentration issue as a % of deal flow comes from annual contracts giving access to a big-box chain. The owner has maintained this contract for 10+ years. Happy to answer any questions.