Where in the city are you working? PATH is $2.75 a ride, so $5.50 a day. You can get passes giving you multiple trips on the same card called Smartlink, here's the link for the website
Fares - PATH - The Port Authority of NY & NJ
PATH is generally pretty quick. Aside from any occasional issues on the line, like a disabled train or some emergency or general train traffic, there are usually no problems. The ride from Newark to WTC, for example, is about 20-25 minutes and it makes 5 stops, the fifth being WTC. I like the PATH. I call it a "classier subway" because at rush hour it's generally clean and full of commuters wearing business clothing. It's generally a quiet ride at rush hour and no one bothers others. It can be a little different outside of rush hour though.