Hello,I live in a pretty hot market, with very low vacancy rates and high property demand. 

My goal: create an interest-free loan which is appealing to a potential homebuyer, yet doesn't make too big of a discount on my end.For example: If I sold my $300,000 house with 20% down ($60,000) over 30 years, at 6.7% interest rate: $1548.67 principal and interest per month1548.67 x 12 x 30 = $557,521.20What I would do would offer a lower monthly payment and no usury, but it would effectively be like a prepayment penalty.Arbitrarily, let's say 20% off the monthly payment, or $309.73 less per month: $1238.94 monthly payment.House would be sold at $446,018.40, which is $111,502.8 less than the total paid with a normal mortgage, but $116,018 more than the market price.

Banks and CU have something called "High Cost" rules which means a mortgage under $75K generally is not large enough to include or finance their hard costs plus fee's.Some DSCR lenders offer a $75K minimum after down payment but rates are usually above 9.75% even with good credit and carry a 2-3 year prepayment penalty. 

I think the general consensus with todays rates and prices is that cash flow is not that amazing in any market. 

Your “overhead” costs to buy & sell the house + holding costs, interest, property taxes etc, luckily these can be pretty easily calculated, many websites like closing companies will have websites where you can fill out information about a property and it will tell you the costs to buy & sell, loan costs are easily calculable, take your purchase multiply by intrest rate divide by 12, that’s your monthly expenses multiply by the number of months you project the to complete, a good rule of thumb is even cosmetic can easily be 6 months anything more complicated can be 9-12 though all that can very greatly.3.

And we live in CA so our tax rates are high.

The water is not deep but it's a 5 foot drop down to it.

In my experience, the best rates and terms for home equity products are from credit unions.

Even at a conservative 8% cap rate the building is worth around $1.625M.

When any little hiccup comes along that most of us did not financially prepare for we Demand the GuvMint do something, like my stock portfolio dropped 25% today in 10/87, so drop interest rate to Zero, thanks Maestro Greenspan, or again in 3/2000 when Yahoo.com didn't somehow grow into its projected 30 trillion dollar market cap based on its PE of 700, drop rates to Zero and keep 'em there for 22 years except for brief interludes of sanity (inflation got above 2%), or in 2008 when no one with a pension fund in America took any damn responsibility/oversight and gave their retirement funds to crooks to buy whatever ratings agency rubber stamped dogshit inverse synthetic CDO they could get a commission on, then were shocked, laying on their fainting couch clutching their pearls when the financial system reliably imploded, so drop rates to Zero again and start Monetizing/printing the debt, and now with the most predicted pandemic in history, Americans hadn't saved a damn cent so we cried to the GuvMint, send us 7 Trillion dollars now, I need a new Lambo!