Not sure if you are looking at the same one, but here's my experience for what its worth. I did this about a month ago for About Face, and it was well worth the $150 it paid at the time. It will take 1-2 hours to do the shop and probably an hour to complete the report, maybe less. It was one of the first shops I did as a mystery shopper, so I was much slower at the reporting part.
The real trick is making sure you get the audio recording of the entire interaction. The other trick is making sure you use your own personal information and work any public information about yourself into your back story. They will have you complete a brief online application (basic personal info) and will use your social security number to pull up your financial aid history and qualifications. If you already have a student loan (and maybe other federally funded financial aid) it will show up. So if you've been to college, you shouldn't hide that. I said I was interested in the Massage Therapy program available at the campus I visited, as a mid-life career change opportunity. I had said I only went to college for a few semesters, so it was a little weird when the financial aid counselor reviewed my outstanding student load debt with me. Luckily, I don't think she knew what I had told the admissions rep about dropping out after just 2 semesters.
I'm seeing those shops at $200 now, which in my opinion is well worth the time and effort. This is the best shop I ever did! The real key is making sure you have a reliable way to get a clear recording, since its pretty much a one shot deal. Once you have made the visit you will be in their system, there is no way to go back and re-do the shop at a later date.
Honestly, I would do these shops over and over if it weren't for my information already being in the system. If anyone can tell me other MSCs that do similar shops it would definitely make my day ;-)
I hope this helps.