Disappointed, but, I guess, not surprised

Several years ago, we had an academic customer literally steal our time, our effort, our design, etc. for their system. The signals were there, and we didn’t pay attention to them.
Something like that happened again, though this time we recognized it. Customer still is operating off the assumption that they got something for nothing, but … well … when they put their system together, discover that it doesn’t work, I expect a few probing emails.
Here is the game they play: Start out asking you for a quote that they use to win a grant. They then come back with something else, not high performance, and not realistic for their use case. You then, politely explain the differences, not in sufficient detail that they have engineering diagrams, but in sufficient detail that they should understand the differences.
Then, because they are, I dunno, smarter than the average bear, mebbe? they decide to go shopping for parts with this new information. And they indicate that they are about to order something. Never mind that you can see that it is profoundly wrong, you can see all the problems with their design.
They are iterating their design by asking you to criticize it. Point out the weaknesses. They are using you as an unpaid consultant.
So, do the obvious thing. Wish them luck, indicate your profound regret that they chose to steal information and value rather than buy value, and suggest the future consulting is available at our normal rates.
The original university to do this to us was a big name in Washington DC. This is a big name in NY.
Sad, but not unexpected. In both cases, we simply will refuse future business from these groups (or in the case of the DC folks, the university).
And FWIW, their updated design is badly broken. I mean … its laughable. Shows a profound lack of understanding of some very basic principles. Marginally better than their other one, but not by much.