Invoice price is $24,675 (I copied this from a post on another forum...don't remember where so don't ask for proof)
A good price in Toronto for the WRX is something like $1500.00 off (may have changed by now) as of last year. That's about a 6% profit. Going from that, you'd save about $800 off an RS.
cars4u.com lists a $723.00 discount off the RS right now which coincides with my numbers.
RS's are actually probably harder to get since dealers seem to want to order more WRX's in general.