There's a fun concept that roams around about Roman slavery! Most of what you hear when you hear about the Romans and their slaves is that slaves could be anything from teachers, artists, house servants, musicians, sex slaves, and more, generally with the idea that they would be freed eventually. It all honestly sounds rather glamourous, a bit romantic (No pun intended, I promise!), and, especially because these skilled slaves were often paid, not half bad of a gig, eh? Hell, it'd probably be better than working at Mickey Dee's 60 hours a week for basically enough to live, no?

The big problem there is that it's...well....mostly a misconception. "Roman slaves" were as stratified by location and class as they were anything else, but the vast majority of the slaves in Rome were ... unpampered, to put it mildly. If you'd like a description of the non-city slaves - who generally did not earn a wage - I did a writeup on them here. The TL;DR of that? You did not want to be a slave in the ancient world.

Even city slaves weren't necessarily well-treated. The whores were not paid for their services, the serving girls - as mentioned in the above link - could be raped whenever their owner felt like it, and generally the only slaves who earned that wage that you're talking about would be the "1%" of the slaves. These slaves were either the extremely skilled (such as teachers or historians), who could expect to be freed eventually, or the close household slaves, who would be treated as a part of the household, similar to a favourite pet. The latter often developed an intense loyalty to their masters, and would often defend their masters to the death - or follow him there themselves. Most often, though, the only 'wages' a slave could earn would be the ones he...well...earned himself. If a slave had a talent and could monetize it - sculpting, for example - he could make things in his spare time and possibly earn enough to free himself - if their master helped them out. The most famous example of this is Eurysaces the Baker.

Hope that helps you out a bit :)