The original contract stated " Install re - purposed roof tile, buy and install about 600 sq ft of new roof tiles". Since the color can't match to original color we can;t use the old tile and have buy all new tile roof. The contractor sent me a quote for new roof tile total SQ 21.35 for my 1510 sq ft house from roof tile company on 9/4/2019. I agreed to pay my share which is 15.35 SQ. Now He stated that SQ number is not right. He increased to 34 SQ from 21.35 SQ (which is 1265 sq ft more )and asked me pay more. I believed that He play money game and wanted me to pay his part 600 sq ft . Shall I pay this increase number.