Not magic but rather hard work. There are no rules and through hard work you find the exceptions. Last year I found a probate sale in Encinitas on a great townhome. It was in late December and everyone else was cowering in the corner. We got an acceptance at 285K and them my buyer join the cowering crowd in the corner and someone else picked it up for 300K. In March it could have easily sold for 375K. One year later it still would easily sell for 325 to 350K. I cant imagine it ever dropping below 250K. It was a moment in time that I caught and my buyer dropped. There really isnt another property like this one so no amount of magic can work better later. No magic there.
To answer yuour question as to the percentage, I’d make a wild assed guess that it would be 1 or 2% if not less that can be bought at great prices and are what most buyers actually want. Good luck finding one.It aint e-z.