A manual unit costs less but takes 20 minutes to change settings. A motorized unit with a digital controller can cycle through 20 sun positions in 2 minutes. If you are doing iterative design, the automation pays for itself in billable hours.
A desk lamp casts light that spreads out (diverges). The real sun is 93 million miles away, so its rays are almost perfectly parallel. To simulate this accurately, expensive units use long-throw distances or precision mirrors. Better collimation = Higher price. heliodon price
But when you start shopping for one, the sticker shock is real. Prices range from a few hundred dollars for a DIY kit to over $100,000 for a precision research instrument. A manual unit costs less but takes 20