I think you might be extending this model beyond its boundaries of usefulness.

Well it's a theoretical economics concept. The $20 bill is an opportunity, nothing more. A pretty good deal of course, but if you are pedantic you could defend the standpoint that you did have to do something to get it: first, get lucky enough to be there, notice it, then bend over and maybe clean it. So it's not "free", just a pretty good deal.

The same thing applies to getting a job for instance. Take job X. If job X was available and worth doing at wage $, someone would be doing it. So why bother applying ?

So what it really means is that the semi-strong and strong form of the efficient market hypothesis is bullshit: there are plenty of opportunities in the market, you're just not seeing most of them.

I would argue that nearly everyone doesn't even try to see opportunities.