And even very experienced developers get in trouble with budget overruns, material costs through the roof, and unreliable subcontractors. 

I'm trying to buy a 4 plex, and live in one of the units.The problem is that the rents are currently too low for the apartments to cash flow with all four units, and the rents would just barely cover the mortgage if I lived in one of the units.I could live there practically for free but what would I do when I wanted to move?

And if one year you unexpectedly need to replace a roof and a furnace, that place needs cash instead of generating it.So I'd be curious about how much you have to invest and how much you need to gain in monthly cash flow. 

Sure if there is enough margin to cover both mortgages.

I spent one weekend reading the Arizona landlord/tenant laws cover to cover and definitely think it was well worth my time.

If you're at 75% or less, you should be able to get long term money, even if it's alternative - 30 year ARMs at rates in the 6-8% range, as long as debt service works (rents cover PITI).The other one seems doable too, if same type of deal w/no work. 

. $533 is not enough to cover OpEx, CapEx, Debt Service, and Profit.

There are a number of short term interest only products that will only cover the purchase price but those rates are typically still going to be a bit high 

For instance; if you are looking at property that has 2 units under one roof and another 2 units under another roof, is this a Quad?

I ended up putting about 20% down and then offered her an equity split on GROSS earnings for 2 years to cover the rest.