i guess $2.50psf only applies to an area that's more than 200sqft.. that's what an ID i went to told me.. i asked him the same questions too,..smaller than 200 sqft is lump sum charge. if they come and do just a 25sqft ceiling and charge you $62.50, how can they cover even their transport cost and labour, not even to mention material cost? And if the false ceiling comes with an upturn or light box, it's additional charge too.