want to lay ceramic tile in kitchen, entry, and bath. thinking 13" square tile laid diangle. will need cement board too. are jobs done by the sq. ft., or by hour? bath & entry have small closet, and L shaped bar in kitchen. this will be about 250sq ft total. just wondering (ballpark) what i could expect to pay, and if installers would be interested in a small job like this by ft. or hr.