Don't your rule and corollary disagree?

This is one of those things that's incredibly context dependent. There are lots of fat cat small companies out there who do easy tasks with thick margins. There are also jobs that are deceptively hard which it makes sense to hire out.

I usually try to err on the side of diy, but everyone has a different threshold on these things. Sometimes the economics work out when you don't count your time.

Probably? I mean, I knew I could get the jointer moved cheaper myself, because I have an idea what a competent rigger costs[0]. I just couldn't do it myself with that level of skill. Watch some YouTube videos of people doing rigging. The good ones are very good.

For the record, I didn't want to do the job myself because 1700 pounds moving in the wrong direction didn't sound like a bad time. I tried getting a quote to see if it was within the range I was willing to pay to not have to do it myself. When it came back at the cost of my truck rental, I couldn't see any way they could be charging enough to be good. Like, you wouldn't pay $15 to get a cavity filled. I would've tried getting more quotes, but the seller had a deadline.

[0] I went to an auction at a defunct furniture company. As the bids were finalized, a rigging company went around leaving quotes on the heavier machines for how much it would cost to move them. $700 doesn't move a lot of cast iron, and it certainly doesn't get it moved 4 hours away.