If the RS comes out in similar trim to the FoST, I would be willing to guess:
ST1 trim about $33K
ST2 trim about $35.5K
ST3 trim about $39K
Speculating, of course. I'm in no position to do anything otherwise.
If I were a betting man, I'd say your estimates are pretty darn close!!
EDIT: RS1, RS2, RS3?
IIRC I heard the RS will be/was offered in the past with 2 option sets only... At least it was on the MK2 Focus RS
"Spec-wise, Ford offered two option packs. Luxury Pack 1 featured dual-zone climate control, automatic headlights and wipers, rear parking sensors, tyre pressure monitoring, keyless go, DAB radio and a Sony six-disc CD player. Luxury Pack 2 came on top, replacing the hi-fi with a Ford system including a rear-view camera and touch-screen satnav. Air-con was standard on all versions"
So i'm assuming a barebones stock and a "Luxury Pack" with all of the Recaro's/Nav goodies. I'm assuming its going to be a well optioned base model, with the "luxury" bits saved for that pack. That said... they are offering two tire options which I think will be additional to either one, and recaro buckets might be standard. Just blowing wind but I think:
$35k base
$41k fully optioned out with Cup 2 rubber and all (if that option makes it to the states). I think it has to be high if its limited, but still priced to compete strongly in the market. Honestly, it should be more expensive than an STi as it will warrant it in both performance and interior options. We shall see.