.....especially since he did talk to the people who make and sell them. I think he is right that it would be "incredibly expensive". I imagine the manufacturers said that as well.
You've got it all in one paragraph there. If you talk to the sales team, who "sell" the engines, I am sure they licked their lips at the prospect of selling some additional units to a research study into the issue. "Yes, Mr Study-Leader, it is most unfortunate that what you want to study is Incredibly Expensive." Especially if it looks like a government-sponsored project, when the typical government-sponsored project approach of sales teams would apply (ie take your normal price to the commercial world and multiply by 10).