Actually I didnt. The full fairing on the "F" is 4 plastic pieces total . However I didnt include any of the fasteners /screws in totals (either model).
Unfortunately pricing motorcycles (or anything else for that matter) isn't as simple as this. No amount of plastic components or fasteners would account for the difference in price. Styling in itself can demand a higher price. I can honestly tell you that if the F model wasn't available I wouldn't have purchased the naked.
The naked version is likely priced to compete against other naked bikes with similar displacement. Thereby the competitors' pricing strategy would directly be reflected in what Suzuki picks for an MSRP figure. If say Honda prices the CB1000R ~ 11k it would make sense for Suzuki to undercut them slightly in their effort to gain market share. Other motorcycles competing for the same customer would have more to do with the final figure than the cost of a few components do.
If Suzuki's marketing department determined that a particular customer shopping for the GSX-S1000F would also be looking at say F800GT or Z1000, they can afford to make a lightly better margin on that model.
All things aside I consider both models to be priced extremely competitively, even if there's a slight disparity between the two, they are both aggressively priced.
Another more surprising thing, to me, is why aren't they selling better considering the low asking price. Had Suzuki decided to factor in a higher marketing cost of promoting both models, they would have likely cost a bit more, but presumably resulted in more units in the hands of customers. We can only ponder.