how much cost does thunderbolt add to a laptop?

[pman6]

depending on quantities ordered,
Regular usb-c controllers cost $3-5.
Thunderbolt 3 controllers cost $5-8

http://ark.intel.com/products/87401/Intel-DSL6340-Thunderbolt-3-Controller

If the price difference is so little, why aren't more laptops using thunderbolt?
Just add the $3 to the msrp.

eh?

 

[corkyg]

Basically because of royalties to Apple and high cost of cable.