In the past they had some where you had to check the temperatures of their hot and cold food, check the temperature log books to make sure they were taking regular readings, and several other items. I think these paid around $15-20.
There were also some about a year and a half ago that I did, but not for $50.
You had to actually inventory items from a list and see how many of each were on a shelf. I think it took me about 45-60 minutes to do these. I only did two, but I'm sure I could have gotten the time down after I did a few.