Simple supply and demand, you don't need some crazy spreadsheet to see that.

Here is what I proposed:Setup fees : Administration Setup:One Time Fee: $400Guidebook: Using professional photos give the guests a professional tour of the house and how the home works (Wifi passwords // How to use grill // How to use propane fireplace // Hot tub instructions // Sauna instructions //Check in and check out instructions //where extras may be storedOTA (Online Travel Agency) setups: taking professional photos and actively updating your listing on popular platforms;PMS (Property Management System) Setup Smart Pricing Set upWebsite integrationOther (furniture arrangement / design / décor shopping and set up) $50 per hour· Placement fees · Marketing Cost: Variable depending on needs/wants for marketingFacebook AdsGoogle Ads Cleaners: Set up procedures/take pics of expectations· Management fee—30%Guest communicationCleaner communicationSetting Rental rateDealing with small maintenance issuesBooking CoordinationSmart Lock integrationKeeping supplies stocked (TP, paper towel, all cleaning products, coffee, filters, creamer, sugars, teas,)(Receipts would be submitted on a monthly basis for either reimbursement or book keeping purposes)Encouraging guests to leave good reviews by periodically checking in, providing a review template, and ensuring guests receive the amenities they are looking forContinued marketingMajor Maintenance fees—OwnerCleaning and laundry services fees: Cleaning fee to the guest depending on how cleaner wants to charge

The crash of 2008 was caused by a combination of lax lending standards, the supply of money flooding the market and over construction.

If economy tanks, recession, depression, people can't afford squat, RENTS GO UP. because the demand for the supply will be insane.    

Your best bet is likely going to be trying to figure out some sort of seller-financing, or bring on a partner to the deal that can supply the additional cash. 

Just supply and interest rates crushed us.

@Kaleb DeCook depends on supply & demand!

Is the City of Pomona prepared to lose 10% of its rental unit supply (2300+ units)?

The key is to know the market including the supply and the demand in the area. 

You potentially could do a partership with someone who could supply the money for a downpayment.