Prices for porcelain countertops are usually cheaper than quartz and can be cheaper than granite, but not always. The average cost of porcelain installed is $55 - $85 compared to quartz at $65 - $90 and the average price of granite at $45 - $65 per square foot. However, rare or exotic granite countertops can cost $200+/sq. ft., and both porcelain and quartz can cost as much as $120/psf. So, it's never a cut-and-dried comparison.