Blood of Rome
Ancient Rome is a slave-owning society, and slaves are embedded in the social structure to the point that some slaves own slaves themselves. Slave markets are, therefore, a standard part of the commercial structure of the city, and very, very few residents of Rome are uncomfortable with the idea of finding human beings for sale, even those Romans who are human beings themselves.
Human beings are quite large, and intelligent and strong enough to escape pens that would hold most animals. People held to be sold as slaves are also motivated to escape, although the penalties meted out to those who do, and are caught, serve as some deterrent. This means that a slave market has to be quite large, with significant levels of security, and this tends to push slave markets to the outskirts of the city.
Slaves are normally sold at auction, exhibited naked to potential buyers, and, if appropriate, made to demonstrate their skills. As might be expected, young and attractive slaves fetch good prices, but slaves with valuable skills also bring in the money; the highest recorded price paid for a slave was for a teacher of Greek, back in the days of the Republic. Skilled slaves can find themselves running significant portions of the Empire, if they happen to be bought by the Emperor’s representatives, so skilled slaves have an interest in demonstrating their abilities to the full. Unskilled slaves tend to end up on farms or in mines, both of which are not far from a death sentence.
A slave market, thus, should make modern players uncomfortable. If people are buying tutors or managers, the slaves try just as hard to impress as job applicants today, while when overseers are looking for galley crews or miners, slaves do their best to appear enfeebled, and good only for clerical work.
In addition, the accommodations are not as bad as might be imagined; sick or dead slaves cannot be sold, at least not for much money. Although the slaves are generally chained to stop them running away, they are normally housed and fed somewhat better than people awaiting trial for crimes. Slave markets do, however, tend to be eerily quiet, as the traders do not want the slaves talking among themselves, and possibly plotting escape.