Sure there's a difference, but when you can buy the base lens for $100 and 3D print your own cinema housing for $50, it becomes a lot more odious that IronGlass is charging what amounts to around $2100USD for a metal rehousing that is at most $50 worth of materials and a few hours work per lens.

The "Cinema" industry is notorious for gouging its customers, and this just yet another particularly egregious example of that gouging.