Their niche will soon figure out there are some people (like OP) running the same software on much better hardware for much lower price. How much longer do you think they will keep buying original macs?
i could almost turn "could macs be good value?" into a mandatory interview question, because those who say no don't understand how trading money for time works. working with such fools is incredibly tedious and painful.
I would advise against that, unless you are in the habit of interviewing people who value their time at $200+ per hour, such as in your above example. Otherwise, their answer may be coming from a slightly different mindset.
Most people who buy Macs are not very price-sensitive, and they decidedly buy them so they don't have to personally build that "much better hardware".
So, this option does exist, but it's the exact opposite about what they want.
Assuming they even need the increased power in the first place, which most (except creatives pros in video and 3D) don't.