ActualAs an example of the problem of Rentometer data, I looked up four recently rented properties on the MLS and compared the Rentometer prediction to the actual rental rate.

From a cash flow perspective, you’d really need to think long and hard about the cost of leveraging these properties, especially in the current rate market.Yes a bigger purchase price might mean a greater potential of higher gross cash flow and appreciation, but that cash flow might get eroded fairly quickly if these moderate interest rates are here to stay.- REI CPA from CA

However, if it needs that much work you are probably better off going with a hard money loan and then doing a rate & term refi once rehabbed.

Does it make sense to pay a premium for cheap interest rates with seller financing, or would it just be better to put 25% and forget about my 15% criteria and just go for distressed sellers and just get a commercial loan. 

First, I would raise the rent slightly higher than market rate and see if the smoker stays.

To address this, we agreed that I would work in the business for six months to verify the financials, which so far align with his POS system.My main issue is that at 23, I don't have strong financials to get a conventional loan at 75% LTV with a ~7% rate, and the seller's lack of financials complicates bank approval.

If I remember correctly, the redemption rate in CHS county is something like 80-90% and the interest that can be earned is capped.

At that time, the builder will pay the accumulated interest along with the principal.We have discussed a few different options to structure this arrangement, assuming an interest rate for interest-only loans with monthly payments is 10%:Option 1: delayed interest with a rate of 12% (interest rate is 2% higher)Option 2: charge a lower interest of 8% then profit share (need to determine appropriate % split)Any other thoughts on how to structure this arrangement?

As someone else mentioned I think that Househacking a multi family is your best bet and the recommendation I give to everyone looking to get started or even someone looking to buy their first home.House hack is the easiest barrier to entry becasue your cost for downpayment can be as little as 3.5% FHA or 5% conventional, and you usually get the best rates as a primary residence borrower. 

I then thought of the idea to offer they a fixed rate if they private lended me cash on a short term (5-10 year) period.