Take buyers and sellers of technology services out to coffee and ask what they buy/sell and what they would buy/sell but for the impossibility of finding it in the market.
For example, you could take me out to coffee. It's no secret what I would tell you there, since it is practically in 50ft tall fire letters on my blog: When I was consulting, I made systems which made software companies lots of money, most typically by applying engineering tactics to marketing/sales ends for them. The prototypical deliverable was "Your SaaS app now sends a lifecycle email campaign." My sweet-spot client is a software company with $10 million to $50 million a year in annual sales. (There exist hundreds of these, most of whom will never even be mentioned on HN, in any context.) I am not particularly a supergenius with copywriting -- I just apply a bit of formula, horse sense, and personal experience with experimentation, and it works much of the time. I picked it up with a bit of reading and a lot of doing. Do I think that the average HNer could do this 6 weeks after having announced an intention to seriously start doing this? Yes. Can my average consulting client find someone to do this full-time for them? No, not for love or money. Do I think this niche would support a consultancy full-time? Yes. This tiny little sliver of the global economy would support ten clones of my consultancy, selling 30 weeks a year, without coming close to satisfying market demand for this service.
Price is a signal that the market generates to cue potential service providers that there exists unsatisfied demand for a service. The fact that the market does not clear in e.g. marketing technology or cryptosystem verification or what have you, even at rates in the $20k+ a week region, should signal "Well, that would be a lucrative practice to be in."