The TB is nowhere near $200 extra. The price jump from the nTB MBP to the TB MBP is $300 and for that $300 you get:
* Upgrade from dual-core 7th gen processor to quad-core 8th gen processor
* Improved retina display (true-tone)
* Two additional thunderbolt 3 ports
* IRIS Plus Graphics 655 (upgrade from 640)
* The touch bar itself
The touch bar is only a portion of the overall $300 price increase. While none of us know for sure what the actual breakdown is, it seems unlikely to me that it accounts for a full two-thirds of the difference given the scope of the other upgrades.
Apple do not offer any way for us to directly compare the pricing differential since there's no current product where you can spec with or without the touchbar with everything else being equal.