I would have to guess it would take 10+ hours if you include the help you are asking on this forum + reading all the instructions.And it will still produce the wrong result. 10 hours or 40 hours later.I have over 20 years of experience, and I would not try to do it by hand.

what is it exactly about the listings that isn't producing results?

If you stuff 200+ envelopes for an real producer they will give you some real good pointers and maybe eventually bring you on.  

Therefore, interest rates have some measurable impact on the value of income-producing real estate. 

Making sure the cost is below comps would allow me to back out if the Airbnb did not produce any revenue.

AIRBNB and the like, can produce a strong and steady income (game days, graduation, events, greek life,etc).

When you consider all the fees included, and the value of your time spent, a vacation rental will often produce less income than a long-term rental.

Great testimony on how preparation and action produce results.  

That 400K would be producing about 1K per month of cash flow, AND gaining about 18K per year in equity!

With Private Money you can get a quality rental now that will produce  cashflow to support your fix and flips.