Menu price increase - erumxm.boszkowo-akwawit.pl Determine the prime costs per guest Prime Cost per guest = Labour cost per guest + menu item's food cost $6.55 = $2.80 + $3.75 3. The authors analyze 884 Internet-based restaurant menus from inside and outside San Jose, California, which they collected before and after the city implemented a 25% minimum wage increase in 2013.