I would not waste an opportunity to get a discount from the sellers and close on time, possibly a significant one.  

The IRR is by far the more accurate of the two because it discounts cash flows for time and opportunity cost, however both metrics in some form juxtapose the cash outlays against the cash in-flows.With this in mind, the biggest cash outflow is the down-payment - the larger the down-payment, the harder you'll have to work to recover it and drive the ROI.Does this answer your question?

Thanks everyone to all the great advice this is a tremendous help!

I'm just wondering, what is the success rate of finding a motivated seller who's willing to sell his property at a discount deep enough so that the deal turns out to be a good one? 

Investor loans with zero points are typically .50 to .625% higher, so 4.75 to 4.875% (or alternatively you can take the 4.25% O/O rate and pay 1.75% investor discount points, that decision depends on how long you might hold, usually better for investors to take the higher rate as you're doing).The fees paid to the lender (processing, underwriting, NOT 3rd party pass-through like appraisal, title work, closing) should be no more than about $500; there can be alot of variability here, and it can be negotiable.

You get the arbitrage on the payments, unless you ask for discount points.

As far as links, I have a tremendous amount of information I've put together that if you dig on the net long enough you can find, but some of the useful links to good info are no longer out there since we are talking about stuff from 5 years ago.

If the estate has adequate assets to cover the judgment, you would seek out the lien holder and ask for an option on settling the lien (or Buying it at a discount).

Happy to help with any Realtor needs you have or give any rental or sales data you need.  1% Realtor discount to BP members.

When you acquire 1/2 dozen, or more, properties you can begin to get some discounts when you purchase all of your insurance through one agent and increase deductibles but it is very much worth the effort to keep the premiums low.