How much would it cost to keep a slave in modern day?

I was just having a talk with someone who works for minimum wage, about work and pay and the economy, and I got wondering about this.

If I owned a slave, and I had to feed the slave enough that it would not die or become too sick to do the job, and I had to clothe it and give it shelter, and had to transport it between the shelter and the work site, and had to provide very basic medical care. What amount of money would I need each year to keep the slave?

Bonus question: How does owning and working a slave stack up versus paying someone minimum wage?