Another method is you can search for comps in the area to find a duplex that is similar to your subject property - check the rent of duplexes nearby and make estimates.

Don't depend on Airdna to be accurate enough.Use the enemy method.

Does anyone have any creative ideas on how to structure the financing so that we aren't floating a huge monthly payment before the business even opens? 

Have you had success with social media marketing, email campaigns, direct mail, or any other methods?

If not we could work out a down payment with cash, and finance the repairs through our day jobs. 

Once you figure out the payment schemes, next you have to see what kind of resources they have to help you. 80% of real estate agents fail or only make like 40k a year so you have to avoid those people and only focus on finding a niche.

The real estate strategies that have been resonating with me so far are house hacking, multi-family buildings, and the BRRR method.

It absolutely could...jumping on this new BRRRR method!

I approach any guarantee of returns as a red flag, unless it's clearly outlined with a payment schedule, as all investments entail risk.

Honestly most methods work but you got to stick to one at first.