Surprised about the stratospheric prices quote for dynamo lighting. As I've delineated before, you can set up (and I did) a modern, quality dynamo light system for under $100US with a B&M IQ Fly + Dymotec6 or Axa Traction. Slick little system.
Having own the Ixon Iq which was the battery version of the Fly ($70), I found it to dim to recommend. (It's very different than the Ixon Iq Premium that's available now).
The Cyo was the first light bright enough, in my opinion, to be used as a regular front light. The Eyc seems to be the latest equivalent, at $80 to the Cyo. However, if I was doing it myself, I think the $30 extra for the Cyo Premium is definitely worth it for the wider beam.
Are you thinking of a sidewall dynamo in your calculations? The cheapest decent dynamo hub I know of is the Sanyo h27, I think it's $60 just for the hub, and $135 for a rebuild wheel, though admittedly I feel like there must be cheaper sources.