The MR-2 couldn't have been cheaper than the Sprinter Truneo / Levin. Neither would have been the Celica.
The 86/BRZ will always be the cheapest brother, unless they revive the Starlet (but this is basically the Yaris).
I think Toyota really had at least 5 brothers in the sporty department not just 3.
This SF-R is a revival of the Sera at best.