""""""""""and let's face it, if the engineer/photographer could do the service you offer for the price you
charge, then why would they be coming to you in the first place? =)""""""""

I suppose that would be the point. Asking the engineer to do a bunch of heavy lifting to get you the model, when he already told his boss it would be $1000, not $200. So the engineer sends an OBJ/STL and says, "good luck"....