From your linked site I see you are expecting a cost of about $2250 to get a kit shipped. What all comes in this kit? What was the average MPG going to be?
I built a tail and a nose cone for my car for about $600-700 so I am wondering what is driving that cost?
If I do a bit of ROI calcs:
If i could get the bike for ~$1000 and a kit for $2250 I would have to save a lot of $$$ per year to make the ROI work. reregistration and insurance would be several hundred a year so that would make the ROI a long time indeed for me as I only spend about $1100 in gas a year. If you doubled my MPG to 100 I would half my fuel cost and then after the costs for the bike each year I would save $200 but In MI you cannot ride all year at best you can get 8 months of the year. so at best I would break even each year. If it got 150 MPG then it would save me a net of about $300 a year. thats 3 or more years for the bike then how long for the kit?
Now if I got 30 mpg and wanted the extra risk of riding a bike it would be a fun project