People receive the same pay for disparate effort all the time in this world. Besides, unlimited differences in remuneration could still exist in the form of benefits--only no one would be able to claim the "fruits of the labor," in the form of revenue, of employees. In any event, as an individual you could be anything you wanted to be and make as much money as you could in the market. Also, private property would still exist. So it can't be "marxism"--but there could be no taxes.