You've just confirmed it even more!

In terms of appraisal accuracy, 90 percent of appraisals come in above the purchase and sale agreement, which may suggest a bit of confirmation bias on behalf of the appraiser whereby they are justifying the contract price rather than independently arriving at the value.

Your main costs will be Property Tax, Property Insurance, Maintenance (small repairs, landscaping, pest control, etc), Capital Expenditures Reserve aka Cap Ex (money set aside for roof, HVAC, Flooring, etc), Vacancy, Property Management, and then any debt service you have on the property.

You will want to check with your 457 administrator to confirm. 

Thanks for the confirmation

Also be sure to somehow confirm rent amounts (estoppel letters).

One thing to make sure is to manually set your minimum nights to allow the shorter reservations for that window. 

Also to buy only properties where I can add value and/or have built-in equity as a bit of a cushion for if/when the market takes a dip.It’s not that I’m expecting to sell anytime soon, but I’d like to have the option to sell and the extra equity created allows me to do that.Finally keeping plenty of cash reserves and sources of capital open (lines of credit, private money).

Then I run BP /calc to confirm. 

You could get 2 solid B/B+ cash flow rentals in Birmingham with 20% down and have some cash left over as reserves.