I spoke to the Sales Office and here are the prices for the current Residence 3 and 3X's for Phase 15:
Lot 128: Plan 3X: $1,244,400 (Larger lot).
Lot 125: Regular Plan 3: $1,254,300 (Larger lot).
Lot 122 Regular Plan 3: $1,179,300 (Smaller lot).
So is Lot 121 a 2X and not a 3X?
I'm not sure...