This seller bought it for 7700 and selling it for 40k.

The owner has an LLC that he uses because it is a business for him to sell property and finance it for individuals.

Deal ended up falling through and selling maybe 18 months later.

We're just 6 months into payments, and want to keep the loan if we sell the tiny home to build out an attached ADU to code.  

Maximizing profits when selling an investment property involves strategic planning and execution.

If for example a home is selling for $225,000 it will have an estimate of $1,462/month.With 25% down the calculator shows: $1,023 per month Principal and interest $806Property taxes$125Homeowners insurance$92How can I get a better idea of the total including everything? 

Maybe you partner with someone who can take on the work while you are selling cars.

I would appreciate any advice on figuring out what we could charge for rent so that we can decide if selling or renting is our best option. 

I've seen a few STRs sell for 20-30% higher than neighboring comps.

My experience has been that this only occurs when a 'turn key' provider over-rents a property in order to sell it to an out of state investor.