@Faith Importico 100% time and resources. There are multiple deals where we did not do very well (break-even or slight profit) but the effort expended was not a ton. We recently flipped a condo and made a whopping $400. Total dud.
However, a couple years ago we flipped a rural property and it was a complete nightmare. We ended up making about $20k on it, but it was a huge drain of our time and energy. I would 100% rather do the $400 condo deal versus that one. Even if we lost $10-20k on a deal where the effort is minimal, I'd choose that over the nightmare property that makes money but ruins your life.
If you gave me the choice between making $1,000,000 on a deal that is going to take a long time, will require tons of effort and time, and will not allow me to pursue many other additional ventures VS. A deal I'd make $75-100k on that is a routine house flip with nothing out of the ordinary, I would choose the 2nd option in a heartbeat.
You can always make more money, time is invaluable!