If all those who are currently earning $1000 are paid $1500 instead, then those who are currently earning $1500 will demand that their salaries be increased to $2000 or more in order to maintain the differential. The supervisors of these people will then ask for a higher salary too. After all, you can't have a supervisor of security guards earning the same salary of those reporting to him.
The chain reaction will inflate the wage bill significantly and the increase in overheads will have to be passed on to the customers.
The net result will be an increase in overall costs and the resulting inflation will mean that $1500 will buy what previously cost only $1000.
Higher wages cannot be legislated. They have to be earned via the free market mechanism.