Ah, well I got my info from a Car and Driver article.
https://www.caranddriver.com/feature...2019/?slide=10
Anyhow, I'd think a few bits of curved tubular steel and 1 less wheel would substantially reduce the cost over an intricately designed and machined unibody vehicle.
UTVs start around $3k and some seat many people. You'd think a 2-seater trike would be a piece of cake.
I built a reverse trike in highschool using tubular aluminum, custom machined bicycle wheels, lead acid batteries, and a 2hp DC motor and controller.