Arranging to sign SPA recently, realised that the adjustment rate is not based on the SPA price divide by unit parcel area. For example: SPA price is RM1,000,000 parcel size 1,110, shouldn't the adjustment rate is RM900.90 per sqft (RM1mil /1110 sqf) ? I was told by lawyer and sales person it's based on total constriction cost divided by total size for the project, is this something right since the adjustment rate is applicable only if there is vary to my own parcel unit against with the individual strata title but nothing to do with the common area. Hope someone here can help and if your SPA also spell out the same term.
Thanks alot in advance.

Adjustment rate if actual size as per strata title is less than the size as per SPA (brochure or whatever they determined), the developer will need to pay back to the purchaser on the difference, probably this might be rare case but just want an assurance.